检测到新建 CVE Issue，CVE-ID: CVE-2026-89927。
你可以通过以下两种方式使用 CVE 修复服务：
-
分支影响分析
- 在本 Issue 下评论：
/analysis_branches - 系统将自动分析各个分支是否受影响，并在本 Issue 下给出表格形式的分析结果；
- 在本 Issue 下评论：
-
在指定分支上创建 PR（修复提交）
- 在本 Issue 下按如下格式评论（
branch、name、email为必填字段，每个字段单独一行）：
- 在本 Issue 下按如下格式评论（
/create_pr
branch: OLK-6.6 OLK-5.10
name: dev
email: dev@devstation.com
backport-engine: opencode
- 说明：
branch: 需要创建 PR 的目标分支列表，例如OLK-6.6 OLK-5.10；name: PR 签名人姓名（如责任人或安全负责人）；email: PR 签名人邮箱；backport-engine（可选）：可选portgpt、mystique或opencode；不填时默认使用opencode；
系统会根据上述信息自动在指定分支上创建 PR，并在本 Issue 下反馈结果。
provided by DevStation.
issue处理注意事项:
1. 提交正常修复分支的修复PR时,必须关联当前issue,否则无法关闭当前issue;
2. 模板内容需要填写完整, 无论是受影响或者不受影响都需要填写完整内容;
3. 以下为模板中需要填写完整的内容, 请复制到评论区回复;
注: 内容的关键词(影响性分析说明, openEuler评分, 受影响版本排查(受影响/不受影响), 修复是否涉及abi变化(是/否), 原因说明)不能省略,省略后cve-manager将无法正常解析填写内容.
影响性分析说明:
openEuler评分: (评分和向量)
受影响版本排查(受影响/不受影响):
1.master(6.18.40):
2.openEuler-20.03-LTS-SP4(4.19.90):
3.openEuler-22.03-LTS-SP4(5.10.0):
4.openEuler-24.03-LTS-Next(6.6.0):
5.openEuler-24.03-LTS-SP1(6.6.0):
6.openEuler-24.03-LTS-SP3(6.6.0):
7.openEuler-24.03-LTS-SP4(6.6.0):
修复是否涉及abi变化(是/否)：
1.master(6.18.40):
2.openEuler-20.03-LTS-SP4(4.19.90):
3.openEuler-22.03-LTS-SP4(5.10.0):
4.openEuler-24.03-LTS-Next(6.6.0):
5.openEuler-24.03-LTS-SP1(6.6.0):
6.openEuler-24.03-LTS-SP3(6.6.0):
7.openEuler-24.03-LTS-SP4(6.6.0):
原因说明：
1.master(6.18.40):
2.openEuler-20.03-LTS-SP4(4.19.90):
3.openEuler-22.03-LTS-SP4(5.10.0):
4.openEuler-24.03-LTS-Next(6.6.0):
5.openEuler-24.03-LTS-SP1(6.6.0):
6.openEuler-24.03-LTS-SP3(6.6.0):
7.openEuler-24.03-LTS-SP4(6.6.0):
原因说明填写请参考下方表格(注意：版本是否受影响和版本的原因说明必须对应，例如master版本分支受影响，那原因说明只能是受影响对应的原因之一!)：
分支状态 |
原因说明 | 使用场景 |
|---|---|---|
| 受影响 | 正常修复 | 受影响且需要修复（包含升级版本修复）的漏洞； 受影响且已经修复的漏洞（历史修复PR也需要关联issue）； 若因特殊原因无法修复，应修改原因说明为【不修复-特殊原因】，并在安委会备案相关情况。 |
| 受影响 | 暂不修复-漏洞仍在分析中 | 已关注到相关漏洞，正在处理，未明确漏洞影响和修复方案。 |
| 受影响 | 暂不修复-暂无解决方案或补丁 | 当前没有可用的修复或补救措施。【影响性分析】中应包含有关为什么没有修复或补救措施的详细说明、上游相关PR等。 |
| 受影响 | 不修复-超出修复范围 | 没有漏洞的修复计划。当版本停维、软件包宣布生命周期终止或弃用使用。 |
| 受影响 | 不修复-特殊原因导致不再修复 | 如存在其他特殊情况不修复相关漏洞，或评估后无法升级修复，应在openEuler社区安全委员会例会进行说明备案。 【影响性分析】中应包含不发布修复的详细说明、特殊情况还应有安委会会议纪要。 |
| 不受影响 | 不受影响-组件不存在 | 软件不受影响，因为易受攻击的组件不在产品中。 |
| 不受影响 | 不受影响-已有内置的内联控制或缓解措施 | 内置的内联控制或缓解措施可防止攻击者利用漏洞 |
| 不受影响 | 不受影响-漏洞代码不能被攻击者触发 | 易受攻击的组件存在，并且该组件包含易受攻击的代码。但是，易受攻击的代码的使用方式使得攻击者无法进行任何预期的攻击。 |
| 不受影响 | 不受影响-漏洞代码不在执行路径 | 易受影响的代码在执行过程中不可访问，包括产品的非预期状态。产品不使用也不执行的组件。 |
| 不受影响 | 不受影响-漏洞代码不存在 | 产品不受影响，因为漏洞背后的代码在产品中不存在。与component_not_present不同的是，有问题的组件存在，但由于某种原因（例如安全的编译器选项）使漏洞的特定代码不存在于组件中。 |
issue处理具体操作请参考:
https://atomgit.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
pr关联issue具体操作请参考:
https://docs.atomgit.com/docs/help/home/org_project/pullrequests/pr-related-issue
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说明：补丁链接仅供初步排查参考，实际可用性请人工再次确认，补丁下载验证可使用CVE补丁工具。
若补丁不准确，烦请在此issue下评论 '/report-patch 参考网址 补丁链接1,补丁链接2' 反馈正确信息，便于我们不断优化工具，不胜感激。
如 /report-patch https://security-tracker.debian.org/tracker/CVE-2021-3997 https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1
CVE-2026-89927
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns ticks. These timers
may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
When the timer is enabled, stimer_start() translates COUNT to an
absolute monotonic deadline and arms an hrtimer. If COUNT is set to a
value close to U64_MAX, the deadline calculation can overflow.
ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))
This can result in a CPU livelock. stimer_start() arms the timer
via hrtimer_start() with a deadline in the past, which causes it to
immediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, with
the intention of causing KVM to deliver a synthetic interrupt on the
next vCPU guest enter.
Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes the
request, calling kvm_hv_process_stimers(). This would normally disable
the timer via stimer_expiration() once the deadline is in the past.
However, the deadline comparison is done between the KVM reference
counter and stime->exp_time, which is a big value close to U64_MAX, so
this never happens for a few thousand years.
kvm_hv_process_timers() then re-arms the timer via stimer_start(), since
it was not disabled, which again fires immediately. Before entering
the guest, kvm_vcpu_exit_request() checks kvm_request_pending(),
which returns true due to the newly raised KVM_REQ_HV_STIMER. Then
vcpu_enter_guest() aborts the guest entry, returning early into
vcpu_run(), which loops back again into vcpu_enter_guest(), restarting
the cycle.
Since there are no manual yields in this loop, a task with SCHED_FIFO
may starve RCU grace-period kthreads, which exposes the stalls found
by syzcaller:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
( ... )
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900040a7320 EFLAGS: 00000206
RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64
hrtimer_start include/linux/hrtimer.h:259 [inline]
stimer_start arch/x86/kvm/hyperv.c:682 [inline]
kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893
vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline]
vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639
kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984
kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f635278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358
</TASK>
Fix this by clamping the deadline computation to KTIME_MAX, which
preserves the intent of arming a timer very far in the future.
ktime_add_safe() already does this type of clamping, so use it after
checking that that multiplying by the 100ns time tick also does not
overflow.
[sean: tag for stable]
The Linux kernel CVE team has assigned CVE-2026-89927 to this issue.
openEuler评分:(评分和向量)
7.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.master:不受影响
2.openEuler-20.03-LTS-SP4:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.openEuler-24.03-LTS:受影响
6.openEuler-24.03-LTS-Next:不受影响
7.openEuler-24.03-LTS-SP1:受影响
8.openEuler-24.03-LTS-SP2:受影响
9.openEuler-24.03-LTS-SP3:受影响
10.openEuler-24.03-LTS-SP4:受影响
修复是否涉及abi变化(是/否)：
1.master:否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS-SP3:否
4.openEuler-22.03-LTS-SP4:否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-24.03-LTS-SP1:否
8.openEuler-24.03-LTS-SP2:否
9.openEuler-24.03-LTS-SP3:否
10.openEuler-24.03-LTS-SP4:否
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:暂不修复-漏洞仍在分析中
3.openEuler-22.03-LTS-SP3:不修复-超出修复范围
4.openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中
5.openEuler-24.03-LTS:不修复-超出修复范围
6.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
7.openEuler-24.03-LTS-SP1:暂不修复-漏洞仍在分析中
8.openEuler-24.03-LTS-SP2:不修复-超出修复范围
9.openEuler-24.03-LTS-SP3:暂不修复-漏洞仍在分析中
10.openEuler-24.03-LTS-SP4:暂不修复-漏洞仍在分析中
openeuler-ci-bot@wkfxxx 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 分析项目 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64 hrtimer_start include/linux/hrtimer.h:259 [inline] stimer_start arch/x86/kvm/hyperv.c:682 [inline] kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893 vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline] vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f635278f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358 </TASK>Fix this by clamping the deadline computation to KTIME_MAX, whichpreserves the intent of arming a timer very far in the future.ktime_add_safe() already does this type of clamping, so use it afterchecking that that multiplying by the 100ns time tick also does notoverflow.[sean: tag for stable]The Linux kernel CVE team has assigned CVE-2026-89927 to this issue. |
| 已分析 | 2.openEulerScore | 7.1 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | master:不受影响,openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP4:受影响,openEuler-24.03-LTS-Next:不受影响,openEuler-24.03-LTS-SP1:受影响,openEuler-24.03-LTS-SP3:受影响,openEuler-24.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-24.03-LTS:受影响,openEuler-24.03-LTS-SP2:受影响 |
| 已分析 | 5.是否涉及abi变化 | master:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP4:否,openEuler-24.03-LTS-Next:否,openEuler-24.03-LTS-SP1:否,openEuler-24.03-LTS-SP3:否,openEuler-24.03-LTS-SP4:否,openEuler-22.03-LTS-SP3:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-SP2:否 |
| 已分析 | 6.原因说明 | master:不受影响-漏洞代码不能被攻击者触发,openEuler-20.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发,openEuler-24.03-LTS-SP1:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-SP3:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-22.03-LTS-SP3:不修复-超出修复范围,openEuler-24.03-LTS:不修复-超出修复范围,openEuler-24.03-LTS-SP2:不修复-超出修复范围 |
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CVE-2026-89927
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns ticks. These timers
may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
When the timer is enabled, stimer_start() translates COUNT to an
absolute monotonic deadline and arms an hrtimer. If COUNT is set to a
value close to U64_MAX, the deadline calculation can overflow.
ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))
This can result in a CPU livelock. stimer_start() arms the timer
via hrtimer_start() with a deadline in the past, which causes it to
immediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, with
the intention of causing KVM to deliver a synthetic interrupt on the
next vCPU guest enter.
Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes the
request, calling kvm_hv_process_stimers(). This would normally disable
the timer via stimer_expiration() once the deadline is in the past.
However, the deadline comparison is done between the KVM reference
counter and stime->exp_time, which is a big value close to U64_MAX, so
this never happens for a few thousand years.
kvm_hv_process_timers() then re-arms the timer via stimer_start(), since
it was not disabled, which again fires immediately. Before entering
the guest, kvm_vcpu_exit_request() checks kvm_request_pending(),
which returns true due to the newly raised KVM_REQ_HV_STIMER. Then
vcpu_enter_guest() aborts the guest entry, returning early into
vcpu_run(), which loops back again into vcpu_enter_guest(), restarting
the cycle.
Since there are no manual yields in this loop, a task with SCHED_FIFO
may starve RCU grace-period kthreads, which exposes the stalls found
by syzcaller:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
( ... )
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900040a7320 EFLAGS: 00000206
RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64
hrtimer_start include/linux/hrtimer.h:259 [inline]
stimer_start arch/x86/kvm/hyperv.c:682 [inline]
kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893
vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline]
vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639
kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984
kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f635278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358
</TASK>
Fix this by clamping the deadline computation to KTIME_MAX, which
preserves the intent of arming a timer very far in the future.
ktime_add_safe() already does this type of clamping, so use it after
checking that that multiplying by the 100ns time tick also does not
overflow.
[sean: tag for stable]
The Linux kernel CVE team has assigned CVE-2026-89927 to this issue.
openEuler评分:(评分和向量)
7.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.master:不受影响
2.openEuler-20.03-LTS-SP4:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.openEuler-24.03-LTS:受影响
6.openEuler-24.03-LTS-Next:不受影响
7.openEuler-24.03-LTS-SP1:受影响
8.openEuler-24.03-LTS-SP2:受影响
9.openEuler-24.03-LTS-SP3:受影响
10.openEuler-24.03-LTS-SP4:受影响
修复是否涉及abi变化(是/否)：
1.master:否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS-SP3:否
4.openEuler-22.03-LTS-SP4:否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-24.03-LTS-SP1:否
8.openEuler-24.03-LTS-SP2:否
9.openEuler-24.03-LTS-SP3:否
10.openEuler-24.03-LTS-SP4:否
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:暂不修复-漏洞仍在分析中
3.openEuler-22.03-LTS-SP3:不修复-超出修复范围
4.openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中
5.openEuler-24.03-LTS:不修复-超出修复范围
6.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
7.openEuler-24.03-LTS-SP1:暂不修复-漏洞仍在分析中
8.openEuler-24.03-LTS-SP2:不修复-超出修复范围
9.openEuler-24.03-LTS-SP3:暂不修复-漏洞仍在分析中
10.openEuler-24.03-LTS-SP4:暂不修复-漏洞仍在分析中
@wkfxxx 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 分析项目 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64 hrtimer_start include/linux/hrtimer.h:259 [inline] stimer_start arch/x86/kvm/hyperv.c:682 [inline] kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893 vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline] vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f635278f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358 </TASK>Fix this by clamping the deadline computation to KTIME_MAX, whichpreserves the intent of arming a timer very far in the future.ktime_add_safe() already does this type of clamping, so use it afterchecking that that multiplying by the 100ns time tick also does notoverflow.[sean: tag for stable]The Linux kernel CVE team has assigned CVE-2026-89927 to this issue. |
| 已分析 | 2.openEulerScore | 7.1 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | master:不受影响,openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP4:受影响,openEuler-24.03-LTS-Next:不受影响,openEuler-24.03-LTS-SP1:受影响,openEuler-24.03-LTS-SP3:受影响,openEuler-24.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-24.03-LTS:受影响,openEuler-24.03-LTS-SP2:受影响 |
| 已分析 | 5.是否涉及abi变化 | master:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP4:否,openEuler-24.03-LTS-Next:否,openEuler-24.03-LTS-SP1:否,openEuler-24.03-LTS-SP3:否,openEuler-24.03-LTS-SP4:否,openEuler-22.03-LTS-SP3:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-SP2:否 |
| 已分析 | 6.原因说明 | master:不受影响-漏洞代码不能被攻击者触发,openEuler-20.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发,openEuler-24.03-LTS-SP1:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-SP3:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-22.03-LTS-SP3:不修复-超出修复范围,openEuler-24.03-LTS:不修复-超出修复范围,openEuler-24.03-LTS-SP2:不修复-超出修复范围 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
CVE-2026-89927
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns ticks. These timers
may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
When the timer is enabled, stimer_start() translates COUNT to an
absolute monotonic deadline and arms an hrtimer. If COUNT is set to a
value close to U64_MAX, the deadline calculation can overflow.
ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))
This can result in a CPU livelock. stimer_start() arms the timer
via hrtimer_start() with a deadline in the past, which causes it to
immediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, with
the intention of causing KVM to deliver a synthetic interrupt on the
next vCPU guest enter.
Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes the
request, calling kvm_hv_process_stimers(). This would normally disable
the timer via stimer_expiration() once the deadline is in the past.
However, the deadline comparison is done between the KVM reference
counter and stime->exp_time, which is a big value close to U64_MAX, so
this never happens for a few thousand years.
kvm_hv_process_timers() then re-arms the timer via stimer_start(), since
it was not disabled, which again fires immediately. Before entering
the guest, kvm_vcpu_exit_request() checks kvm_request_pending(),
which returns true due to the newly raised KVM_REQ_HV_STIMER. Then
vcpu_enter_guest() aborts the guest entry, returning early into
vcpu_run(), which loops back again into vcpu_enter_guest(), restarting
the cycle.
Since there are no manual yields in this loop, a task with SCHED_FIFO
may starve RCU grace-period kthreads, which exposes the stalls found
by syzcaller:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
( ... )
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900040a7320 EFLAGS: 00000206
RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64
hrtimer_start include/linux/hrtimer.h:259 [inline]
stimer_start arch/x86/kvm/hyperv.c:682 [inline]
kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893
vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline]
vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639
kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984
kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f635278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358
</TASK>
Fix this by clamping the deadline computation to KTIME_MAX, which
preserves the intent of arming a timer very far in the future.
ktime_add_safe() already does this type of clamping, so use it after
checking that that multiplying by the 100ns time tick also does not
overflow.
[sean: tag for stable]
The Linux kernel CVE team has assigned CVE-2026-89927 to this issue.
openEuler评分:(评分和向量)
7.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.master:不受影响
2.openEuler-20.03-LTS-SP4:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.openEuler-24.03-LTS:受影响
6.openEuler-24.03-LTS-Next:不受影响
7.openEuler-24.03-LTS-SP1:受影响
8.openEuler-24.03-LTS-SP2:受影响
9.openEuler-24.03-LTS-SP3:受影响
10.openEuler-24.03-LTS-SP4:受影响
修复是否涉及abi变化(是/否)：
1.master:否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS-SP3:否
4.openEuler-22.03-LTS-SP4:否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-24.03-LTS-SP1:否
8.openEuler-24.03-LTS-SP2:否
9.openEuler-24.03-LTS-SP3:否
10.openEuler-24.03-LTS-SP4:否
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:暂不修复-漏洞仍在分析中
3.openEuler-22.03-LTS-SP3:不修复-超出修复范围
4.openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中
5.openEuler-24.03-LTS:不修复-超出修复范围
6.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
7.openEuler-24.03-LTS-SP1:暂不修复-漏洞仍在分析中
8.openEuler-24.03-LTS-SP2:不修复-超出修复范围
9.openEuler-24.03-LTS-SP3:暂不修复-漏洞仍在分析中
10.openEuler-24.03-LTS-SP4:暂不修复-漏洞仍在分析中
@wkfxxx 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 分析项目 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64 hrtimer_start include/linux/hrtimer.h:259 [inline] stimer_start arch/x86/kvm/hyperv.c:682 [inline] kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893 vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline] vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f635278f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358 </TASK>Fix this by clamping the deadline computation to KTIME_MAX, whichpreserves the intent of arming a timer very far in the future.ktime_add_safe() already does this type of clamping, so use it afterchecking that that multiplying by the 100ns time tick also does notoverflow.[sean: tag for stable]The Linux kernel CVE team has assigned CVE-2026-89927 to this issue. |
| 已分析 | 2.openEulerScore | 7.1 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | master:不受影响,openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP4:受影响,openEuler-24.03-LTS-Next:不受影响,openEuler-24.03-LTS-SP1:受影响,openEuler-24.03-LTS-SP3:受影响,openEuler-24.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-24.03-LTS:受影响,openEuler-24.03-LTS-SP2:受影响 |
| 已分析 | 5.是否涉及abi变化 | master:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP4:否,openEuler-24.03-LTS-Next:否,openEuler-24.03-LTS-SP1:否,openEuler-24.03-LTS-SP3:否,openEuler-24.03-LTS-SP4:否,openEuler-22.03-LTS-SP3:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-SP2:否 |
| 已分析 | 6.原因说明 | master:不受影响-漏洞代码不能被攻击者触发,openEuler-20.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发,openEuler-24.03-LTS-SP1:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-SP3:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-22.03-LTS-SP3:不修复-超出修复范围,openEuler-24.03-LTS:不修复-超出修复范围,openEuler-24.03-LTS-SP2:不修复-超出修复范围 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
/create_pr
branch: OLK-6.6 OLK-5.10
name: Zhang Kunbo
email: zhangkunbo@huawei.com
CVE: CVE-2026-89927 · Workflow: a9881aa5fd6448848d55f3b2a00ee54d · Attempt: 1
状态：已结束
| 分支 | 状态 | PR / 错误 | 结果说明 |
|---|---|---|---|
| OLK-6.6 | succeeded | https://gitcode.com/openeuler/kernel/merge_requests/28703 [source: cve_manager: selected] | |
| OLK-5.10 | succeeded | https://gitcode.com/openeuler/kernel/merge_requests/28704 [source: cve_manager: selected] |
CVE-2026-89927
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns ticks. These timers
may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
When the timer is enabled, stimer_start() translates COUNT to an
absolute monotonic deadline and arms an hrtimer. If COUNT is set to a
value close to U64_MAX, the deadline calculation can overflow.
ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))
This can result in a CPU livelock. stimer_start() arms the timer
via hrtimer_start() with a deadline in the past, which causes it to
immediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, with
the intention of causing KVM to deliver a synthetic interrupt on the
next vCPU guest enter.
Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes the
request, calling kvm_hv_process_stimers(). This would normally disable
the timer via stimer_expiration() once the deadline is in the past.
However, the deadline comparison is done between the KVM reference
counter and stime->exp_time, which is a big value close to U64_MAX, so
this never happens for a few thousand years.
kvm_hv_process_timers() then re-arms the timer via stimer_start(), since
it was not disabled, which again fires immediately. Before entering
the guest, kvm_vcpu_exit_request() checks kvm_request_pending(),
which returns true due to the newly raised KVM_REQ_HV_STIMER. Then
vcpu_enter_guest() aborts the guest entry, returning early into
vcpu_run(), which loops back again into vcpu_enter_guest(), restarting
the cycle.
Since there are no manual yields in this loop, a task with SCHED_FIFO
may starve RCU grace-period kthreads, which exposes the stalls found
by syzcaller:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
( ... )
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900040a7320 EFLAGS: 00000206
RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64
hrtimer_start include/linux/hrtimer.h:259 [inline]
stimer_start arch/x86/kvm/hyperv.c:682 [inline]
kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893
vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline]
vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639
kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984
kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f635278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358
</TASK>
Fix this by clamping the deadline computation to KTIME_MAX, which
preserves the intent of arming a timer very far in the future.
ktime_add_safe() already does this type of clamping, so use it after
checking that that multiplying by the 100ns time tick also does not
overflow.
[sean: tag for stable]
The Linux kernel CVE team has assigned CVE-2026-89927 to this issue.
openEuler评分:(评分和向量)
7.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.master:不受影响
2.openEuler-20.03-LTS-SP4:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.openEuler-24.03-LTS:受影响
6.openEuler-24.03-LTS-Next:不受影响
7.openEuler-24.03-LTS-SP1:受影响
8.openEuler-24.03-LTS-SP2:受影响
9.openEuler-24.03-LTS-SP3:受影响
10.openEuler-24.03-LTS-SP4:受影响
修复是否涉及abi变化(是/否)：
1.master:否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS-SP3:否
4.openEuler-22.03-LTS-SP4:否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-24.03-LTS-SP1:否
8.openEuler-24.03-LTS-SP2:否
9.openEuler-24.03-LTS-SP3:否
10.openEuler-24.03-LTS-SP4:否
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:不修复-超出修复范围
3.openEuler-22.03-LTS-SP3:不修复-超出修复范围
4.openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中
5.openEuler-24.03-LTS:不修复-超出修复范围
6.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
7.openEuler-24.03-LTS-SP1:正常修复
8.openEuler-24.03-LTS-SP2:不修复-超出修复范围
9.openEuler-24.03-LTS-SP3:正常修复
10.openEuler-24.03-LTS-SP4:正常修复
@wkfxxx 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 分析项目 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64 hrtimer_start include/linux/hrtimer.h:259 [inline] stimer_start arch/x86/kvm/hyperv.c:682 [inline] kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893 vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline] vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f635278f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358 </TASK>Fix this by clamping the deadline computation to KTIME_MAX, whichpreserves the intent of arming a timer very far in the future.ktime_add_safe() already does this type of clamping, so use it afterchecking that that multiplying by the 100ns time tick also does notoverflow.[sean: tag for stable]The Linux kernel CVE team has assigned CVE-2026-89927 to this issue. |
| 已分析 | 2.openEulerScore | 7.1 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | master:不受影响,openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP4:受影响,openEuler-24.03-LTS-Next:不受影响,openEuler-24.03-LTS-SP1:受影响,openEuler-24.03-LTS-SP3:受影响,openEuler-24.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-24.03-LTS:受影响,openEuler-24.03-LTS-SP2:受影响 |
| 已分析 | 5.是否涉及abi变化 | master:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP4:否,openEuler-24.03-LTS-Next:否,openEuler-24.03-LTS-SP1:否,openEuler-24.03-LTS-SP3:否,openEuler-24.03-LTS-SP4:否,openEuler-22.03-LTS-SP3:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-SP2:否 |
| 已分析 | 6.原因说明 | master:不受影响-漏洞代码不能被攻击者触发,openEuler-20.03-LTS-SP4:不修复-超出修复范围,openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中,openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发,openEuler-24.03-LTS-SP1:正常修复,openEuler-24.03-LTS-SP3:正常修复,openEuler-24.03-LTS-SP4:正常修复,openEuler-22.03-LTS-SP3:不修复-超出修复范围,openEuler-24.03-LTS:不修复-超出修复范围,openEuler-24.03-LTS-SP2:不修复-超出修复范围 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
经过cve-manager解析，部分分支PR未合入，如红色字体所示：
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:不修复-超出修复范围
3.openEuler-22.03-LTS-SP4:暂不修复-漏洞仍在分析中
4.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
5.openEuler-24.03-LTS-SP1:正常修复(PR未合入)
6.openEuler-24.03-LTS-SP3:正常修复(PR未合入)
7.openEuler-24.03-LTS-SP4:正常修复(PR未合入)
8.openEuler-22.03-LTS-SP3:不修复-超出修复范围
9.openEuler-24.03-LTS:不修复-超出修复范围
10.openEuler-24.03-LTS-SP2:不修复-超出修复范围
CVE-2026-89927
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
Fix an issue where userspace or the guest can program an Hyper-V
synthetic timer to have a deadline in the past via integer overflow,
preventing the CPU from making progress and triggering an RCU stall.
Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
guest, which are emulated by KVM. Each is programmed through the
HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
on CONFIG, COUNT represents either the absolute expiration time or the
period of a periodic timer, both expressed in 100ns ticks. These timers
may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
When the timer is enabled, stimer_start() translates COUNT to an
absolute monotonic deadline and arms an hrtimer. If COUNT is set to a
value close to U64_MAX, the deadline calculation can overflow.
ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))
This can result in a CPU livelock. stimer_start() arms the timer
via hrtimer_start() with a deadline in the past, which causes it to
immediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, with
the intention of causing KVM to deliver a synthetic interrupt on the
next vCPU guest enter.
Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes the
request, calling kvm_hv_process_stimers(). This would normally disable
the timer via stimer_expiration() once the deadline is in the past.
However, the deadline comparison is done between the KVM reference
counter and stime->exp_time, which is a big value close to U64_MAX, so
this never happens for a few thousand years.
kvm_hv_process_timers() then re-arms the timer via stimer_start(), since
it was not disabled, which again fires immediately. Before entering
the guest, kvm_vcpu_exit_request() checks kvm_request_pending(),
which returns true due to the newly raised KVM_REQ_HV_STIMER. Then
vcpu_enter_guest() aborts the guest entry, returning early into
vcpu_run(), which loops back again into vcpu_enter_guest(), restarting
the cycle.
Since there are no manual yields in this loop, a task with SCHED_FIFO
may starve RCU grace-period kthreads, which exposes the stalls found
by syzcaller:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
( ... )
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900040a7320 EFLAGS: 00000206
RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64
hrtimer_start include/linux/hrtimer.h:259 [inline]
stimer_start arch/x86/kvm/hyperv.c:682 [inline]
kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893
vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline]
vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639
kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984
kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f635278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358
</TASK>
Fix this by clamping the deadline computation to KTIME_MAX, which
preserves the intent of arming a timer very far in the future.
ktime_add_safe() already does this type of clamping, so use it after
checking that that multiplying by the 100ns time tick also does not
overflow.
[sean: tag for stable]
The Linux kernel CVE team has assigned CVE-2026-89927 to this issue.
openEuler评分:(评分和向量)
7.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.master:不受影响
2.openEuler-20.03-LTS-SP4:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.openEuler-24.03-LTS:受影响
6.openEuler-24.03-LTS-Next:不受影响
7.openEuler-24.03-LTS-SP1:受影响
8.openEuler-24.03-LTS-SP2:受影响
9.openEuler-24.03-LTS-SP3:受影响
10.openEuler-24.03-LTS-SP4:受影响
修复是否涉及abi变化(是/否)：
1.master:否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS-SP3:否
4.openEuler-22.03-LTS-SP4:否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-24.03-LTS-SP1:否
8.openEuler-24.03-LTS-SP2:否
9.openEuler-24.03-LTS-SP3:否
10.openEuler-24.03-LTS-SP4:否
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:不修复-超出修复范围
3.openEuler-22.03-LTS-SP3:不修复-超出修复范围
4.openEuler-22.03-LTS-SP4:正常修复
5.openEuler-24.03-LTS:不修复-超出修复范围
6.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
7.openEuler-24.03-LTS-SP1:正常修复
8.openEuler-24.03-LTS-SP2:不修复-超出修复范围
9.openEuler-24.03-LTS-SP3:正常修复
10.openEuler-24.03-LTS-SP4:正常修复
@wkfxxx 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 分析项目 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000814e64 hrtimer_start include/linux/hrtimer.h:259 [inline] stimer_start arch/x86/kvm/hyperv.c:682 [inline] kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893 vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline] vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f635278f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f635365c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f63529e5fa0 RCX: 00007f635278f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f6352813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63529e6038 R14: 00007f63529e5fa0 R15: 00007ffd5b219358 </TASK>Fix this by clamping the deadline computation to KTIME_MAX, whichpreserves the intent of arming a timer very far in the future.ktime_add_safe() already does this type of clamping, so use it afterchecking that that multiplying by the 100ns time tick also does notoverflow.[sean: tag for stable]The Linux kernel CVE team has assigned CVE-2026-89927 to this issue. |
| 已分析 | 2.openEulerScore | 7.1 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | master:不受影响,openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP4:受影响,openEuler-24.03-LTS-Next:不受影响,openEuler-24.03-LTS-SP1:受影响,openEuler-24.03-LTS-SP3:受影响,openEuler-24.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-24.03-LTS:受影响,openEuler-24.03-LTS-SP2:受影响 |
| 已分析 | 5.是否涉及abi变化 | master:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP4:否,openEuler-24.03-LTS-Next:否,openEuler-24.03-LTS-SP1:否,openEuler-24.03-LTS-SP3:否,openEuler-24.03-LTS-SP4:否,openEuler-22.03-LTS-SP3:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-SP2:否 |
| 已分析 | 6.原因说明 | master:不受影响-漏洞代码不能被攻击者触发,openEuler-20.03-LTS-SP4:不修复-超出修复范围,openEuler-22.03-LTS-SP4:正常修复,openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发,openEuler-24.03-LTS-SP1:正常修复,openEuler-24.03-LTS-SP3:正常修复,openEuler-24.03-LTS-SP4:正常修复,openEuler-22.03-LTS-SP3:不修复-超出修复范围,openEuler-24.03-LTS:不修复-超出修复范围,openEuler-24.03-LTS-SP2:不修复-超出修复范围 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
经过cve-manager解析，部分分支PR未合入，如红色字体所示：
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:不修复-超出修复范围
3.openEuler-22.03-LTS-SP4:正常修复(PR未合入)
4.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
5.openEuler-24.03-LTS-SP1:正常修复(PR未合入)
6.openEuler-24.03-LTS-SP3:正常修复(PR未合入)
7.openEuler-24.03-LTS-SP4:正常修复(PR未合入)
8.openEuler-22.03-LTS-SP3:不修复-超出修复范围
9.openEuler-24.03-LTS:不修复-超出修复范围
10.openEuler-24.03-LTS-SP2:不修复-超出修复范围
经过cve-manager解析，部分分支PR未合入，如红色字体所示：
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:不修复-超出修复范围
3.openEuler-22.03-LTS-SP4:正常修复
4.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
5.openEuler-24.03-LTS-SP1:正常修复(PR未合入)
6.openEuler-24.03-LTS-SP3:正常修复(PR未合入)
7.openEuler-24.03-LTS-SP4:正常修复(PR未合入)
8.openEuler-22.03-LTS-SP3:不修复-超出修复范围
9.openEuler-24.03-LTS:不修复-超出修复范围
10.openEuler-24.03-LTS-SP2:不修复-超出修复范围
经过cve-manager解析，部分分支PR未合入，如红色字体所示：
原因说明：
1.master:不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4:不修复-超出修复范围
3.openEuler-22.03-LTS-SP4:正常修复
4.openEuler-24.03-LTS-Next:不受影响-漏洞代码不能被攻击者触发
5.openEuler-24.03-LTS-SP1:正常修复(PR未合入)
6.openEuler-24.03-LTS-SP3:正常修复(PR未合入)
7.openEuler-24.03-LTS-SP4:正常修复(PR未合入)
8.openEuler-22.03-LTS-SP3:不修复-超出修复范围
9.openEuler-24.03-LTS:不修复-超出修复范围
10.openEuler-24.03-LTS-SP2:不修复-超出修复范围
一、漏洞信息 __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d0---truncated---
漏洞编号：CVE-2026-89927
漏洞归属组件：kernel
漏洞归属的版本：4.19.140,4.19.194,4.19.90,5.10.0,6.1.19,6.12.33,6.18.18,6.18.40,6.18.48,6.4.0,6.6.0
CVSS评分：
BaseScore：7.1 High
Vector：CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
漏洞简述：
In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V s SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace:
漏洞公开时间：2026-09-16 18:30:00
漏洞创建时间：2026-09-18 15:22:30
漏洞详情参考链接：
https://nvd.nist.gov/vuln/detail/CVE-2026-89927
更多参考(点击展开)
漏洞分析指导链接：
https://atomgit.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
漏洞数据来源:
七彩瞬析开源风险感知平台
漏洞补丁信息：
详情(点击展开)
二、漏洞分析结构反馈
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:KVM: x86: hyper-v: Clamp stimer deadline to avoid livelockFix an issue where userspace or the guest can program an Hyper-Vsynthetic timer to have a deadline in the past via integer overflow,preventing the CPU from making progress and triggering an RCU stall.Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to theguest, which are emulated by KVM. Each is programmed through theHV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Dependingon CONFIG, COUNT represents either the absolute expiration time or theperiod of a periodic timer, both expressed in 100ns ticks. These timersmay be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).When the timer is enabled, stimer_start() translates COUNT to anabsolute monotonic deadline and arms an hrtimer. If COUNT is set to avalue close to U64_MAX, the deadline calculation can overflow. ktime_add_ns(ktime_now, 100 * (stimer->exp_time - time_now))This can result in a CPU livelock. stimer_start() arms the timervia hrtimer_start() with a deadline in the past, which causes it toimmediately fire. The stimer callback then raises KVM_RQ_HV_STIMER, withthe intention of causing KVM to deliver a synthetic interrupt on thenext vCPU guest enter.Then, once userspace issues KVM_RUN, vcpu_enter_guest() consumes therequest, calling kvm_hv_process_stimers(). This would normally disablethe timer via stimer_expiration() once the deadline is in the past.However, the deadline comparison is done between the KVM referencecounter and stime->exp_time, which is a big value close to U64_MAX, sothis never happens for a few thousand years.kvm_hv_process_timers() then re-arms the timer via stimer_start(), sinceit was not disabled, which again fires immediately. Before enteringthe guest, kvm_vcpu_exit_request() checks kvm_request_pending(),which returns true due to the newly raised KVM_REQ_HV_STIMER. Thenvcpu_enter_guest() aborts the guest entry, returning early intovcpu_run(), which loops back again into vcpu_enter_guest(), restartingthe cycle.Since there are no manual yields in this loop, a task with SCHED_FIFOmay starve RCU grace-period kthreads, which exposes the stalls foundby syzcaller: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=14269, q=1142 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965239-4294954739), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14269 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. ( ... ) Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x408/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900040a7320 EFLAGS: 00000206 RAX: 5de15cb931505900 RBX: 0000000000000a06 RCX: 5de15cb931505900 RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001 RBP: ffffc900040a73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b8628240
openEuler评分：
7.1
Vector：CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
受影响版本排查(受影响/不受影响)：
1.master(6.18.40):不受影响
2.openEuler-20.03-LTS-SP4(4.19.90):受影响
3.openEuler-22.03-LTS-SP4(5.10.0):受影响
4.openEuler-24.03-LTS-Next(6.6.0):不受影响
5.openEuler-24.03-LTS-SP1(6.6.0):受影响
6.openEuler-24.03-LTS-SP3(6.6.0):受影响
7.openEuler-24.03-LTS-SP4(6.6.0):受影响
8.openEuler-22.03-LTS-SP3(5.10.0):受影响
9.openEuler-24.03-LTS(6.6.0):受影响
10.openEuler-24.03-LTS-SP2(6.6.0):受影响
修复是否涉及abi变化(是/否)：
1.master(6.18.40):否
2.openEuler-20.03-LTS-SP4(4.19.90):否
3.openEuler-22.03-LTS-SP4(5.10.0):否
4.openEuler-24.03-LTS-Next(6.6.0):否
5.openEuler-24.03-LTS-SP1(6.6.0):否
6.openEuler-24.03-LTS-SP3(6.6.0):否
7.openEuler-24.03-LTS-SP4(6.6.0):否
8.openEuler-22.03-LTS-SP3(5.10.0):否
9.openEuler-24.03-LTS(6.6.0):否
10.openEuler-24.03-LTS-SP2(6.6.0):否
原因说明：
1.master(6.18.40):不受影响-漏洞代码不能被攻击者触发
2.openEuler-20.03-LTS-SP4(4.19.90):不修复-超出修复范围
3.openEuler-22.03-LTS-SP4(5.10.0):正常修复
4.openEuler-24.03-LTS-Next(6.6.0):不受影响-漏洞代码不能被攻击者触发
5.openEuler-24.03-LTS-SP1(6.6.0):正常修复
6.openEuler-24.03-LTS-SP3(6.6.0):正常修复
7.openEuler-24.03-LTS-SP4(6.6.0):正常修复
8.openEuler-22.03-LTS-SP3(5.10.0):不修复-超出修复范围
9.openEuler-24.03-LTS(6.6.0):不修复-超出修复范围
10.openEuler-24.03-LTS-SP2(6.6.0):不修复-超出修复范围