{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43402","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-01T14:12:56.007Z","datePublished":"2026-05-08T14:21:43.550Z","dateUpdated":"2026-05-11T22:23:53.371Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:23:53.371Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nkthread: consolidate kthread exit paths to prevent use-after-free\n\nGuillaume reported crashes via corrupted RCU callback function pointers\nduring KUnit testing. The crash was traced back to the pidfs rhashtable\nconversion which replaced the 24-byte rb_node with an 8-byte rhash_head\nin struct pid, shrinking it from 160 to 144 bytes.\n\nstruct kthread (without CONFIG_BLK_CGROUP) is also 144 bytes. With\nCONFIG_SLAB_MERGE_DEFAULT and SLAB_HWCACHE_ALIGN both round up to\n192 bytes and share the same slab cache. struct pid.rcu.func and\nstruct kthread.affinity_node both sit at offset 0x78.\n\nWhen a kthread exits via make_task_dead() it bypasses kthread_exit() and\nmisses the affinity_node cleanup. free_kthread_struct() frees the memory\nwhile the node is still linked into the global kthread_affinity_list. A\nsubsequent list_del() by another kthread writes through dangling list\npointers into the freed and reused memory, corrupting the pid's\nrcu.func pointer.\n\nInstead of patching free_kthread_struct() to handle the missed cleanup,\nconsolidate all kthread exit paths. Turn kthread_exit() into a macro\nthat calls do_exit() and add kthread_do_exit() which is called from\ndo_exit() for any task with PF_KTHREAD set. This guarantees that\nkthread-specific cleanup always happens regardless of the exit path -\nmake_task_dead(), direct do_exit(), or kthread_exit().\n\nReplace __to_kthread() with a new tsk_is_kthread() accessor in the\npublic header. Export do_exit() since module code using the\nkthread_exit() macro now needs it directly."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/kthread.h","kernel/exit.c","kernel/kthread.c"],"versions":[{"version":"4d13f4304fa43471bfea101658a11feec7b28ac0","lessThan":"4729c7b00a347fd37d0cbc265b85f2884c3e06b6","status":"affected","versionType":"git"},{"version":"4d13f4304fa43471bfea101658a11feec7b28ac0","lessThan":"5a591d7a5e48d30100943940a30a6ab41b15c672","status":"affected","versionType":"git"},{"version":"4d13f4304fa43471bfea101658a11feec7b28ac0","lessThan":"28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/kthread.h","kernel/exit.c","kernel/kthread.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.18.19","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.9","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/4729c7b00a347fd37d0cbc265b85f2884c3e06b6"},{"url":"https://git.kernel.org/stable/c/5a591d7a5e48d30100943940a30a6ab41b15c672"},{"url":"https://git.kernel.org/stable/c/28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f"}],"title":"kthread: consolidate kthread exit paths to prevent use-after-free","x_generator":{"engine":"bippy-1.2.0"}}}}