{"id":"CVE-2026-80916","revision":"7e2aa789ff6f42aba02598bc895f801b","records":[{"revision":"7e2aa789ff6f42aba02598bc895f801b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80916","aliases":[],"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.","state":0,"publishedAt":"2026-09-09T16:13:14.587+00:00","modifiedAt":"2026-10-19T08:45:00.547+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/sched.h\",\n                        \"kernel/kcov.c\",\n                        \"lib/Kconfig.debug\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"ef7048d8a614c5f5a9b20513a5428101a744514e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"8ed3ddf23d39bf5338406bd9f8863d44748cf6ce\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"5dc59fc959b2b5742985d7ef24bccd1868217dc2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"a2fb8222cde23b0001812ed3acb7c0ea36dd94e2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"18799e858b407bf355383c9dd6c06477aa437134\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"e11f5b48c82703242a3be7a7ae4b4940b4cb4610\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"22670d1552fe155822b2abf91f920925f7d067b4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff3b30ab57da82d8db4f14662a2858cabfbc2c0\",\n                            \"lessThan\": \"2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/sched.h\",\n                        \"kernel/kcov.c\",\n                        \"lib/Kconfig.debug\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.8\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.8\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.269\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.220\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.185\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.154\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.106\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.47\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.11\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.1\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"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"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80916","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80916","identifiers":["CVE-2026-80916"]},"retained":false,"historicalAffected":[]}],"coverage":[]}