FKIE_CVE-2026-45957
Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
rcu: Fix rcu_read_unlock() deadloop due to softirq
Commit 5f5fa7ea89dc ("rcu: Don't use negative nesting depth in
__rcu_read_unlock()") removes the recursion-protection code from
__rcu_read_unlock(). Therefore, we could invoke the deadloop in
raise_softirq_irqoff() with ftrace enabled as follows:
WARNING: CPU: 0 PID: 0 at kernel/trace/trace.c:3021 __ftrace_trace_stack.constprop.0+0x172/0x180
Modules linked in: my_irq_work(O)
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G O 6.18.0-rc7-dirty #23 PREEMPT(full)
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__ftrace_trace_stack.constprop.0+0x172/0x180
RSP: 0018:ffffc900000034a8 EFLAGS: 00010002
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000003 RSI: ffffffff826d7b87 RDI: ffffffff826e9329
RBP: 0000000000090009 R08: 0000000000000005 R09: ffffffff82afbc4c
R10: 0000000000000008 R11: 0000000000011d7a R12: 0000000000000000
R13: ffff888003874100 R14: 0000000000000003 R15: ffff8880038c1054
FS: 0000000000000000(0000) GS:ffff8880fa8ea000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b31fa7f540 CR3: 00000000078f4005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<IRQ>
trace_buffer_unlock_commit_regs+0x6d/0x220
trace_event_buffer_commit+0x5c/0x260
trace_event_raw_event_softirq+0x47/0x80
raise_softirq_irqoff+0x6e/0xa0
rcu_read_unlock_special+0xb1/0x160
unwind_next_frame+0x203/0x9b0
__unwind_start+0x15d/0x1c0
arch_stack_walk+0x62/0xf0
stack_trace_save+0x48/0x70
__ftrace_trace_stack.constprop.0+0x144/0x180
trace_buffer_unlock_commit_regs+0x6d/0x220
trace_event_buffer_commit+0x5c/0x260
trace_event_raw_event_softirq+0x47/0x80
raise_softirq_irqoff+0x6e/0xa0
rcu_read_unlock_special+0xb1/0x160
unwind_next_frame+0x203/0x9b0
__unwind_start+0x15d/0x1c0
arch_stack_walk+0x62/0xf0
stack_trace_save+0x48/0x70
__ftrace_trace_stack.constprop.0+0x144/0x180
trace_buffer_unlock_commit_regs+0x6d/0x220
trace_event_buffer_commit+0x5c/0x260
trace_event_raw_event_softirq+0x47/0x80
raise_softirq_irqoff+0x6e/0xa0
rcu_read_unlock_special+0xb1/0x160
unwind_next_frame+0x203/0x9b0
__unwind_start+0x15d/0x1c0
arch_stack_walk+0x62/0xf0
stack_trace_save+0x48/0x70
__ftrace_trace_stack.constprop.0+0x144/0x180
trace_buffer_unlock_commit_regs+0x6d/0x220
trace_event_buffer_commit+0x5c/0x260
trace_event_raw_event_softirq+0x47/0x80
raise_softirq_irqoff+0x6e/0xa0
rcu_read_unlock_special+0xb1/0x160
__is_insn_slot_addr+0x54/0x70
kernel_text_address+0x48/0xc0
__kernel_text_address+0xd/0x40
unwind_get_return_address+0x1e/0x40
arch_stack_walk+0x9c/0xf0
stack_trace_save+0x48/0x70
__ftrace_trace_stack.constprop.0+0x144/0x180
trace_buffer_unlock_commit_regs+0x6d/0x220
trace_event_buffer_commit+0x5c/0x260
trace_event_raw_event_softirq+0x47/0x80
__raise_softirq_irqoff+0x61/0x80
__flush_smp_call_function_queue+0x115/0x420
__sysvec_call_function_single+0x17/0xb0
sysvec_call_function_single+0x8c/0xc0
</IRQ>
Commit b41642c87716 ("rcu: Fix rcu_read_unlock() deadloop due to IRQ work")
fixed the infinite loop in rcu_read_unlock_special() for IRQ work by
setting a flag before calling irq_work_queue_on(). We fix this issue by
setting the same flag before calling raise_softirq_irqoff() and rename the
flag to defer_qs_pending for more common.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrcu: Fix rcu_read_unlock() deadloop due to softirq\n\nCommit 5f5fa7ea89dc (\"rcu: Don\u0027t use negative nesting depth in\n__rcu_read_unlock()\") removes the recursion-protection code from\n__rcu_read_unlock(). Therefore, we could invoke the deadloop in\nraise_softirq_irqoff() with ftrace enabled as follows:\n\nWARNING: CPU: 0 PID: 0 at kernel/trace/trace.c:3021 __ftrace_trace_stack.constprop.0+0x172/0x180\nModules linked in: my_irq_work(O)\nCPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G O 6.18.0-rc7-dirty #23 PREEMPT(full)\nTainted: [O]=OOT_MODULE\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nRIP: 0010:__ftrace_trace_stack.constprop.0+0x172/0x180\nRSP: 0018:ffffc900000034a8 EFLAGS: 00010002\nRAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000000\nRDX: 0000000000000003 RSI: ffffffff826d7b87 RDI: ffffffff826e9329\nRBP: 0000000000090009 R08: 0000000000000005 R09: ffffffff82afbc4c\nR10: 0000000000000008 R11: 0000000000011d7a R12: 0000000000000000\nR13: ffff888003874100 R14: 0000000000000003 R15: ffff8880038c1054\nFS: 0000000000000000(0000) GS:ffff8880fa8ea000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000055b31fa7f540 CR3: 00000000078f4005 CR4: 0000000000770ef0\nPKRU: 55555554\nCall Trace:\n \u003cIRQ\u003e\n trace_buffer_unlock_commit_regs+0x6d/0x220\n trace_event_buffer_commit+0x5c/0x260\n trace_event_raw_event_softirq+0x47/0x80\n raise_softirq_irqoff+0x6e/0xa0\n rcu_read_unlock_special+0xb1/0x160\n unwind_next_frame+0x203/0x9b0\n __unwind_start+0x15d/0x1c0\n arch_stack_walk+0x62/0xf0\n stack_trace_save+0x48/0x70\n __ftrace_trace_stack.constprop.0+0x144/0x180\n trace_buffer_unlock_commit_regs+0x6d/0x220\n trace_event_buffer_commit+0x5c/0x260\n trace_event_raw_event_softirq+0x47/0x80\n raise_softirq_irqoff+0x6e/0xa0\n rcu_read_unlock_special+0xb1/0x160\n unwind_next_frame+0x203/0x9b0\n __unwind_start+0x15d/0x1c0\n arch_stack_walk+0x62/0xf0\n stack_trace_save+0x48/0x70\n __ftrace_trace_stack.constprop.0+0x144/0x180\n trace_buffer_unlock_commit_regs+0x6d/0x220\n trace_event_buffer_commit+0x5c/0x260\n trace_event_raw_event_softirq+0x47/0x80\n raise_softirq_irqoff+0x6e/0xa0\n rcu_read_unlock_special+0xb1/0x160\n unwind_next_frame+0x203/0x9b0\n __unwind_start+0x15d/0x1c0\n arch_stack_walk+0x62/0xf0\n stack_trace_save+0x48/0x70\n __ftrace_trace_stack.constprop.0+0x144/0x180\n trace_buffer_unlock_commit_regs+0x6d/0x220\n trace_event_buffer_commit+0x5c/0x260\n trace_event_raw_event_softirq+0x47/0x80\n raise_softirq_irqoff+0x6e/0xa0\n rcu_read_unlock_special+0xb1/0x160\n __is_insn_slot_addr+0x54/0x70\n kernel_text_address+0x48/0xc0\n __kernel_text_address+0xd/0x40\n unwind_get_return_address+0x1e/0x40\n arch_stack_walk+0x9c/0xf0\n stack_trace_save+0x48/0x70\n __ftrace_trace_stack.constprop.0+0x144/0x180\n trace_buffer_unlock_commit_regs+0x6d/0x220\n trace_event_buffer_commit+0x5c/0x260\n trace_event_raw_event_softirq+0x47/0x80\n __raise_softirq_irqoff+0x61/0x80\n __flush_smp_call_function_queue+0x115/0x420\n __sysvec_call_function_single+0x17/0xb0\n sysvec_call_function_single+0x8c/0xc0\n \u003c/IRQ\u003e\n\nCommit b41642c87716 (\"rcu: Fix rcu_read_unlock() deadloop due to IRQ work\")\nfixed the infinite loop in rcu_read_unlock_special() for IRQ work by\nsetting a flag before calling irq_work_queue_on(). We fix this issue by\nsetting the same flag before calling raise_softirq_irqoff() and rename the\nflag to defer_qs_pending for more common."
}
],
"id": "CVE-2026-45957",
"lastModified": "2026-05-27T14:48:03.013",
"metrics": {},
"published": "2026-05-27T14:17:12.280",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1f16679a5aa60238466ce339c35f5e82ece60337"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4a4a6e12c9c829be3f74b7206fa8640fc4e1c566"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/979c708e6c9d7fc461daef2dad8b45f22e23464c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c2932e16d8c354404b17123e64daa8e33191e145"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d41e37f26b3157b3f1d10223863519a943aa239b"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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