{"api_version":"1","generated_at":"2026-07-23T14:26:07+00:00","cve":"CVE-2025-39749","urls":{"html":"https://cve.report/CVE-2025-39749","api":"https://cve.report/api/cve/CVE-2025-39749.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-39749","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-39749"},"summary":{"title":"rcu: Protect ->defer_qs_iw_pending from data race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrcu: Protect ->defer_qs_iw_pending from data race\n\nOn kernels built with CONFIG_IRQ_WORK=y, when rcu_read_unlock() is\ninvoked within an interrupts-disabled region of code [1], it will invoke\nrcu_read_unlock_special(), which uses an irq-work handler to force the\nsystem to notice when the RCU read-side critical section actually ends.\nThat end won't happen until interrupts are enabled at the soonest.\n\nIn some kernels, such as those booted with rcutree.use_softirq=y, the\nirq-work handler is used unconditionally.\n\nThe per-CPU rcu_data structure's ->defer_qs_iw_pending field is\nupdated by the irq-work handler and is both read and updated by\nrcu_read_unlock_special().  This resulted in the following KCSAN splat:\n\n------------------------------------------------------------------------\n\nBUG: KCSAN: data-race in rcu_preempt_deferred_qs_handler / rcu_read_unlock_special\n\nread to 0xffff96b95f42d8d8 of 1 bytes by task 90 on cpu 8:\n rcu_read_unlock_special+0x175/0x260\n __rcu_read_unlock+0x92/0xa0\n rt_spin_unlock+0x9b/0xc0\n __local_bh_enable+0x10d/0x170\n __local_bh_enable_ip+0xfb/0x150\n rcu_do_batch+0x595/0xc40\n rcu_cpu_kthread+0x4e9/0x830\n smpboot_thread_fn+0x24d/0x3b0\n kthread+0x3bd/0x410\n ret_from_fork+0x35/0x40\n ret_from_fork_asm+0x1a/0x30\n\nwrite to 0xffff96b95f42d8d8 of 1 bytes by task 88 on cpu 8:\n rcu_preempt_deferred_qs_handler+0x1e/0x30\n irq_work_single+0xaf/0x160\n run_irq_workd+0x91/0xc0\n smpboot_thread_fn+0x24d/0x3b0\n kthread+0x3bd/0x410\n ret_from_fork+0x35/0x40\n ret_from_fork_asm+0x1a/0x30\n\nno locks held by irq_work/8/88.\nirq event stamp: 200272\nhardirqs last  enabled at (200272): [<ffffffffb0f56121>] finish_task_switch+0x131/0x320\nhardirqs last disabled at (200271): [<ffffffffb25c7859>] __schedule+0x129/0xd70\nsoftirqs last  enabled at (0): [<ffffffffb0ee093f>] copy_process+0x4df/0x1cc0\nsoftirqs last disabled at (0): [<0000000000000000>] 0x0\n\n------------------------------------------------------------------------\n\nThe problem is that irq-work handlers run with interrupts enabled, which\nmeans that rcu_preempt_deferred_qs_handler() could be interrupted,\nand that interrupt handler might contain an RCU read-side critical\nsection, which might invoke rcu_read_unlock_special().  In the strict\nKCSAN mode of operation used by RCU, this constitutes a data race on\nthe ->defer_qs_iw_pending field.\n\nThis commit therefore disables interrupts across the portion of the\nrcu_preempt_deferred_qs_handler() that updates the ->defer_qs_iw_pending\nfield.  This suffices because this handler is not a fast path.","state":"PUBLISHED","assigner":"Linux","published_at":"2025-09-11 17:15:38","updated_at":"2026-05-12 13:17:09"},"problem_types":["NVD-CWE-noinfo"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"7","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}}],"references":[{"url":"https://git.kernel.org/stable/c/b55947b725f190396f475d5d0c59aa855a4d8895","name":"https://git.kernel.org/stable/c/b55947b725f190396f475d5d0c59aa855a4d8895","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","name":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Mailing 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git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0864f057b050bc6dd68106b3185e02db5140012d 0ad84d62217488e679ecc90e8628980dcc003de3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0864f057b050bc6dd68106b3185e02db5140012d b5de8d80b5d049f051b95d9b1ee50ae4ab656124 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0864f057b050bc6dd68106b3185e02db5140012d b55947b725f190396f475d5d0c59aa855a4d8895 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0864f057b050bc6dd68106b3185e02db5140012d e35e711c78c8a4c43330c0dcb1c4d507a19c20f4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0864f057b050bc6dd68106b3185e02db5140012d 90de9c94ea72327cfa9c2c9f6113c23a513af60b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.43 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.15.11 6.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.16.2 6.16.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.17 * original_commit_for_fix","platforms":[]},{"source":"ADP","vendor":"Siemens","product":"SIMATIC CN 4100","version":"affected V5.0 custom","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2025","cve_id":"39749","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"linux","cpe5":"linux_kernel","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2025-11-03T17:43:01.289Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"}],"title":"CVE Program Container"},{"affected":[{"defaultStatus":"unknown","product":"SIMATIC CN 4100","vendor":"Siemens","versions":[{"lessThan":"V5.0","status":"affected","version":"0","versionType":"custom"}]}],"providerMetadata":{"dateUpdated":"2026-05-12T12:06:44.240Z","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","shortName":"siemens-SADP"},"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html"}],"x_adpType":"supplier"}],"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["kernel/rcu/tree_plugin.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"74f58f382a7c8333f8d09701aefaa25913bdbe0e","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"f937759c7432d6151b73e1393b6517661813d506","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"0ad84d62217488e679ecc90e8628980dcc003de3","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"b5de8d80b5d049f051b95d9b1ee50ae4ab656124","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"b55947b725f190396f475d5d0c59aa855a4d8895","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"e35e711c78c8a4c43330c0dcb1c4d507a19c20f4","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"90de9c94ea72327cfa9c2c9f6113c23a513af60b","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"55e11f6776798b27cf09a7aa0d718415d4fc9cf5","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"},{"lessThan":"90c09d57caeca94e6f3f87c49e96a91edd40cbfd","status":"affected","version":"0864f057b050bc6dd68106b3185e02db5140012d","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/rcu/tree_plugin.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.3"},{"lessThan":"5.3","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.4.*","status":"unaffected","version":"5.4.297","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.241","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.190","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.149","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.103","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.43","versionType":"semver"},{"lessThanOrEqual":"6.15.*","status":"unaffected","version":"6.15.11","versionType":"semver"},{"lessThanOrEqual":"6.16.*","status":"unaffected","version":"6.16.2","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.17","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.4.297","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.241","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.190","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.149","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.103","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.43","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.15.11","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.16.2","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.17","versionStartIncluding":"5.3","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrcu: Protect ->defer_qs_iw_pending from data race\n\nOn kernels built with CONFIG_IRQ_WORK=y, when rcu_read_unlock() is\ninvoked within an interrupts-disabled region of code [1], it will invoke\nrcu_read_unlock_special(), which uses an irq-work handler to force the\nsystem to notice when the RCU read-side critical section actually ends.\nThat end won't happen until interrupts are enabled at the soonest.\n\nIn some kernels, such as those booted with rcutree.use_softirq=y, the\nirq-work handler is used unconditionally.\n\nThe per-CPU rcu_data structure's ->defer_qs_iw_pending field is\nupdated by the irq-work handler and is both read and updated by\nrcu_read_unlock_special().  This resulted in the following KCSAN splat:\n\n------------------------------------------------------------------------\n\nBUG: KCSAN: data-race in rcu_preempt_deferred_qs_handler / rcu_read_unlock_special\n\nread to 0xffff96b95f42d8d8 of 1 bytes by task 90 on cpu 8:\n rcu_read_unlock_special+0x175/0x260\n __rcu_read_unlock+0x92/0xa0\n rt_spin_unlock+0x9b/0xc0\n __local_bh_enable+0x10d/0x170\n __local_bh_enable_ip+0xfb/0x150\n rcu_do_batch+0x595/0xc40\n rcu_cpu_kthread+0x4e9/0x830\n smpboot_thread_fn+0x24d/0x3b0\n kthread+0x3bd/0x410\n ret_from_fork+0x35/0x40\n ret_from_fork_asm+0x1a/0x30\n\nwrite to 0xffff96b95f42d8d8 of 1 bytes by task 88 on cpu 8:\n rcu_preempt_deferred_qs_handler+0x1e/0x30\n irq_work_single+0xaf/0x160\n run_irq_workd+0x91/0xc0\n smpboot_thread_fn+0x24d/0x3b0\n kthread+0x3bd/0x410\n ret_from_fork+0x35/0x40\n ret_from_fork_asm+0x1a/0x30\n\nno locks held by irq_work/8/88.\nirq event stamp: 200272\nhardirqs last  enabled at (200272): [<ffffffffb0f56121>] finish_task_switch+0x131/0x320\nhardirqs last disabled at (200271): [<ffffffffb25c7859>] __schedule+0x129/0xd70\nsoftirqs last  enabled at (0): [<ffffffffb0ee093f>] copy_process+0x4df/0x1cc0\nsoftirqs last disabled at (0): [<0000000000000000>] 0x0\n\n------------------------------------------------------------------------\n\nThe problem is that irq-work handlers run with interrupts enabled, which\nmeans that rcu_preempt_deferred_qs_handler() could be interrupted,\nand that interrupt handler might contain an RCU read-side critical\nsection, which might invoke rcu_read_unlock_special().  In the strict\nKCSAN mode of operation used by RCU, this constitutes a data race on\nthe ->defer_qs_iw_pending field.\n\nThis commit therefore disables interrupts across the portion of the\nrcu_preempt_deferred_qs_handler() that updates the ->defer_qs_iw_pending\nfield.  This suffices because this handler is not a fast path."}],"providerMetadata":{"dateUpdated":"2026-05-11T21:35:32.172Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/74f58f382a7c8333f8d09701aefaa25913bdbe0e"},{"url":"https://git.kernel.org/stable/c/f937759c7432d6151b73e1393b6517661813d506"},{"url":"https://git.kernel.org/stable/c/0ad84d62217488e679ecc90e8628980dcc003de3"},{"url":"https://git.kernel.org/stable/c/b5de8d80b5d049f051b95d9b1ee50ae4ab656124"},{"url":"https://git.kernel.org/stable/c/b55947b725f190396f475d5d0c59aa855a4d8895"},{"url":"https://git.kernel.org/stable/c/e35e711c78c8a4c43330c0dcb1c4d507a19c20f4"},{"url":"https://git.kernel.org/stable/c/90de9c94ea72327cfa9c2c9f6113c23a513af60b"},{"url":"https://git.kernel.org/stable/c/55e11f6776798b27cf09a7aa0d718415d4fc9cf5"},{"url":"https://git.kernel.org/stable/c/90c09d57caeca94e6f3f87c49e96a91edd40cbfd"}],"title":"rcu: Protect ->defer_qs_iw_pending from data race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-39749","datePublished":"2025-09-11T16:52:21.228Z","dateReserved":"2025-04-16T07:20:57.125Z","dateUpdated":"2026-05-12T12:06:44.240Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-09-11 17:15:38","lastModifiedDate":"2026-05-12 13:17:09","problem_types":["NVD-CWE-noinfo"],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1,"impactScore":5.9}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.4.297","matchCriteriaId":"538D3537-72E6-42E8-A0ED-F5274403F0C4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.241","matchCriteriaId":"D0D21C35-EB8A-488A-BBF9-403E4817E5DD"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.190","matchCriteriaId":"AD9E597F-3DDE-4D7E-976C-463D0611F13F"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.149","matchCriteriaId":"FDBE8280-8983-4D2D-943D-2E6D0104E2D8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.103","matchCriteriaId":"F2293654-7169-49B5-8D0D-EE51EF8B8E48"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.43","matchCriteriaId":"472C5F87-2BF3-4FAB-9B21-DA7513977363"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.15.11","matchCriteriaId":"BC242347-F722-43AE-B910-BE0B22386977"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.16.2","matchCriteriaId":"BD7C087D-2415-4521-B624-30003352F899"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*","matchCriteriaId":"FA6FEEC2-9F11-4643-8827-749718254FED"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"39749","Ordinal":"1","Title":"rcu: Protect ->defer_qs_iw_pending from data race","CVE":"CVE-2025-39749","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"39749","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nrcu: Protect ->defer_qs_iw_pending from data race\n\nOn kernels built with CONFIG_IRQ_WORK=y, when rcu_read_unlock() is\ninvoked within an interrupts-disabled region of code [1], it will invoke\nrcu_read_unlock_special(), which uses an irq-work handler to force the\nsystem to notice when the RCU read-side critical section actually ends.\nThat end won't happen until interrupts are enabled at the soonest.\n\nIn some kernels, such as those booted with rcutree.use_softirq=y, the\nirq-work handler is used unconditionally.\n\nThe per-CPU rcu_data structure's ->defer_qs_iw_pending field is\nupdated by the irq-work handler and is both read and updated by\nrcu_read_unlock_special().  This resulted in the following KCSAN splat:\n\n------------------------------------------------------------------------\n\nBUG: KCSAN: data-race in rcu_preempt_deferred_qs_handler / rcu_read_unlock_special\n\nread to 0xffff96b95f42d8d8 of 1 bytes by task 90 on cpu 8:\n rcu_read_unlock_special+0x175/0x260\n __rcu_read_unlock+0x92/0xa0\n rt_spin_unlock+0x9b/0xc0\n __local_bh_enable+0x10d/0x170\n __local_bh_enable_ip+0xfb/0x150\n rcu_do_batch+0x595/0xc40\n rcu_cpu_kthread+0x4e9/0x830\n smpboot_thread_fn+0x24d/0x3b0\n kthread+0x3bd/0x410\n ret_from_fork+0x35/0x40\n ret_from_fork_asm+0x1a/0x30\n\nwrite to 0xffff96b95f42d8d8 of 1 bytes by task 88 on cpu 8:\n rcu_preempt_deferred_qs_handler+0x1e/0x30\n irq_work_single+0xaf/0x160\n run_irq_workd+0x91/0xc0\n smpboot_thread_fn+0x24d/0x3b0\n kthread+0x3bd/0x410\n ret_from_fork+0x35/0x40\n ret_from_fork_asm+0x1a/0x30\n\nno locks held by irq_work/8/88.\nirq event stamp: 200272\nhardirqs last  enabled at (200272): [<ffffffffb0f56121>] finish_task_switch+0x131/0x320\nhardirqs last disabled at (200271): [<ffffffffb25c7859>] __schedule+0x129/0xd70\nsoftirqs last  enabled at (0): [<ffffffffb0ee093f>] copy_process+0x4df/0x1cc0\nsoftirqs last disabled at (0): [<0000000000000000>] 0x0\n\n------------------------------------------------------------------------\n\nThe problem is that irq-work handlers run with interrupts enabled, which\nmeans that rcu_preempt_deferred_qs_handler() could be interrupted,\nand that interrupt handler might contain an RCU read-side critical\nsection, which might invoke rcu_read_unlock_special().  In the strict\nKCSAN mode of operation used by RCU, this constitutes a data race on\nthe ->defer_qs_iw_pending field.\n\nThis commit therefore disables interrupts across the portion of the\nrcu_preempt_deferred_qs_handler() that updates the ->defer_qs_iw_pending\nfield.  This suffices because this handler is not a fast path.","Type":"Description","Title":"rcu: Protect ->defer_qs_iw_pending from data race"}]}}}