CVE-2026-45957
Full vulnerability record from the local CVENow database.
Description
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.
View original CVE JSON
{
"id": "CVE-2026-45957",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-05-27T14:17:12.280",
"lastModified": "2026-10-30T13:18:54.553",
"vulnStatus": "Modified",
"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't 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 <IRQ>\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 </IRQ>\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."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
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"defaultStatus": "unaffected",
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],
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},
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},
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},
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},
{
"version": "7.0",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.2
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-125"
}
]
}
],
"configurations": [
{
"nodes": [
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