{"id":"CVE-2026-80916","state":"PUBLISHED","title":"kcov: fix data corruption and race conditions on PREEMPT_RT","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nkcov: fix data corruption and race conditions on PREEMPT_RT\n\nsyzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the\ntemporary storage used for saving/restoring remote KCOV state is currently\nallocated as the per-CPU area.\n\nOn PREEMPT_RT kernels, softirq handlers run as preemptible task threads\n(e.g., ksoftirqd). If a softirq context preempts a task running a remote\nKCOV session, it safely saves the task's state into the per-CPU area.\nHowever, if that softirq thread is subsequently preempted by a higher-\npriority softirq thread on the same CPU, the second softirq will overwrite\nthe same per-CPU area, permanently destroying the original task's KCOV\nstate.\n\nFix this data corruption by moving the temporary storage from the per-CPU\narea to the per-thread area. Since each softirq thread now owns its own\ntask context, nested softirq preemption no longer causes data overwrites.\n\nNote that while the temporary storage is now on a per-thread basis, the\nper-CPU kcov_percpu_data.lock must be retained, for we need to ensure that\nkcov_remote_start() and kcov_remote_stop() operate atomically without\nracing against asynchronous interrupts that manipulate the current task's\nKCOV state.\n\nIt is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()\nhas already called panic() before returning NULL, for there will be no\nOOM-killable userspace processes when __init function of built-in module\nruns. But this patch also fixes crashing the kernel when vmalloc_node()\nin kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL\nbut kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in\n\n  (1) doing vmalloc() in kcov_remote_start() despite !in_task() context\n\n  (2) out-of-array-bounds access if (1) succeeded but\n      kcov->remote_size < CONFIG_KCOV_IRQ_AREA_SIZE\n\n  (3) always leak memory allocated by (1), eventually killing all\n      OOM-killable userspace processes\n\nproblems.","publishedAt":"2026-09-09T16:13:14.587Z","updatedAt":"2026-10-19T08:45:00.547Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"ef7048d8a614c5f5a9b20513a5428101a744514e","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"8ed3ddf23d39bf5338406bd9f8863d44748cf6ce","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"5dc59fc959b2b5742985d7ef24bccd1868217dc2","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"a2fb8222cde23b0001812ed3acb7c0ea36dd94e2","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"18799e858b407bf355383c9dd6c06477aa437134","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"e11f5b48c82703242a3be7a7ae4b4940b4cb4610","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"22670d1552fe155822b2abf91f920925f7d067b4","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/sched.h","kernel/kcov.c","lib/Kconfig.debug"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.8","versionType":"semver"},{"version":"5.10.269","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.220","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.185","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.154","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.106","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.47","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.11","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.1","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/sched.h","kernel/kcov.c","lib/Kconfig.debug"]}],"references":["https://git.kernel.org/stable/c/ef7048d8a614c5f5a9b20513a5428101a744514e","https://git.kernel.org/stable/c/8ed3ddf23d39bf5338406bd9f8863d44748cf6ce","https://git.kernel.org/stable/c/5dc59fc959b2b5742985d7ef24bccd1868217dc2","https://git.kernel.org/stable/c/a2fb8222cde23b0001812ed3acb7c0ea36dd94e2","https://git.kernel.org/stable/c/18799e858b407bf355383c9dd6c06477aa437134","https://git.kernel.org/stable/c/e11f5b48c82703242a3be7a7ae4b4940b4cb4610","https://git.kernel.org/stable/c/22670d1552fe155822b2abf91f920925f7d067b4","https://git.kernel.org/stable/c/f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761","https://git.kernel.org/stable/c/2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80916.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80916","state":"PUBLISHED","datePublished":"2026-09-09T16:13:14.587Z","dateUpdated":"2026-10-19T08:45:00.547Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.801Z"},"containers":{"cna":{"title":"kcov: fix data corruption and race conditions on PREEMPT_RT","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nkcov: fix data corruption and race conditions on PREEMPT_RT\n\nsyzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the\ntemporary storage used for saving/restoring remote KCOV state is currently\nallocated as the per-CPU area.\n\nOn PREEMPT_RT kernels, softirq handlers run as preemptible task threads\n(e.g., ksoftirqd). If a softirq context preempts a task running a remote\nKCOV session, it safely saves the task's state into the per-CPU area.\nHowever, if that softirq thread is subsequently preempted by a higher-\npriority softirq thread on the same CPU, the second softirq will overwrite\nthe same per-CPU area, permanently destroying the original task's KCOV\nstate.\n\nFix this data corruption by moving the temporary storage from the per-CPU\narea to the per-thread area. Since each softirq thread now owns its own\ntask context, nested softirq preemption no longer causes data overwrites.\n\nNote that while the temporary storage is now on a per-thread basis, the\nper-CPU kcov_percpu_data.lock must be retained, for we need to ensure that\nkcov_remote_start() and kcov_remote_stop() operate atomically without\nracing against asynchronous interrupts that manipulate the current task's\nKCOV state.\n\nIt is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()\nhas already called panic() before returning NULL, for there will be no\nOOM-killable userspace processes when __init function of built-in module\nruns. But this patch also fixes crashing the kernel when vmalloc_node()\nin kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL\nbut kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in\n\n  (1) doing vmalloc() in kcov_remote_start() despite !in_task() context\n\n  (2) out-of-array-bounds access if (1) succeeded but\n      kcov->remote_size < CONFIG_KCOV_IRQ_AREA_SIZE\n\n  (3) always leak memory allocated by (1), eventually killing all\n      OOM-killable userspace processes\n\nproblems."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"ef7048d8a614c5f5a9b20513a5428101a744514e","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"8ed3ddf23d39bf5338406bd9f8863d44748cf6ce","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"5dc59fc959b2b5742985d7ef24bccd1868217dc2","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"a2fb8222cde23b0001812ed3acb7c0ea36dd94e2","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"18799e858b407bf355383c9dd6c06477aa437134","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"e11f5b48c82703242a3be7a7ae4b4940b4cb4610","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"22670d1552fe155822b2abf91f920925f7d067b4","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761","versionType":"git"},{"version":"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0","status":"affected","lessThan":"2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/sched.h","kernel/kcov.c","lib/Kconfig.debug"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.8","versionType":"semver"},{"version":"5.10.269","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.220","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.185","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.154","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.106","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.47","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.11","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.1","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/sched.h","kernel/kcov.c","lib/Kconfig.debug"]}],"references":[{"url":"https://git.kernel.org/stable/c/ef7048d8a614c5f5a9b20513a5428101a744514e"},{"url":"https://git.kernel.org/stable/c/8ed3ddf23d39bf5338406bd9f8863d44748cf6ce"},{"url":"https://git.kernel.org/stable/c/5dc59fc959b2b5742985d7ef24bccd1868217dc2"},{"url":"https://git.kernel.org/stable/c/a2fb8222cde23b0001812ed3acb7c0ea36dd94e2"},{"url":"https://git.kernel.org/stable/c/18799e858b407bf355383c9dd6c06477aa437134"},{"url":"https://git.kernel.org/stable/c/e11f5b48c82703242a3be7a7ae4b4940b4cb4610"},{"url":"https://git.kernel.org/stable/c/22670d1552fe155822b2abf91f920925f7d067b4"},{"url":"https://git.kernel.org/stable/c/f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761"},{"url":"https://git.kernel.org/stable/c/2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:45:00.547Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"5.10.269"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"5.15.220"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.1.185"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.6.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.12.106"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.18.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"7.1.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"7.2.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","ver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