{"id":"CVE-2026-43292","state":"PUBLISHED","title":"mm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node\n\nWhen CONFIG_PAGE_OWNER is enabled, freeing KASAN shadow pages during\nvmalloc cleanup triggers expensive stack unwinding that acquires RCU read\nlocks.  Processing a large purge_list without rescheduling can cause the\ntask to hold CPU for extended periods (10+ seconds), leading to RCU stalls\nand potential OOM conditions.\n\nThe issue manifests in purge_vmap_node() -> kasan_release_vmalloc_node()\nwhere iterating through hundreds or thousands of vmap_area entries and\nfreeing their associated shadow pages causes:\n\n  rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:\n  rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6229/1:b..l\n  ...\n  task:kworker/0:17 state:R running task stack:28840 pid:6229\n  ...\n  kasan_release_vmalloc_node+0x1ba/0xad0 mm/vmalloc.c:2299\n  purge_vmap_node+0x1ba/0xad0 mm/vmalloc.c:2299\n\nEach call to kasan_release_vmalloc() can free many pages, and with\npage_owner tracking, each free triggers save_stack() which performs stack\nunwinding under RCU read lock.  Without yielding, this creates an\nunbounded RCU critical section.\n\nAdd periodic cond_resched() calls within the loop to allow:\n- RCU grace periods to complete\n- Other tasks to run\n- Scheduler to preempt when needed\n\nThe fix uses need_resched() for immediate response under load, with a\nbatch count of 32 as a guaranteed upper bound to prevent worst-case stalls\neven under light load.","publishedAt":"2026-05-08T13:11:16.017Z","updatedAt":"2026-05-11T22:21:44.094Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"2efa9c02c9b4c0d6866aa445f11056809b25ca28","versionType":"git"},{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"1afe45f89d54b7183768ebbbbf14238ec187ab5c","versionType":"git"},{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"b351fbe71091f7c8676c8ba597653d08b6719447","versionType":"git"},{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"5747435e0fd474c24530ef1a6822f47e7d264b27","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/vmalloc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/vmalloc.c"]}],"references":["https://git.kernel.org/stable/c/2efa9c02c9b4c0d6866aa445f11056809b25ca28","https://git.kernel.org/stable/c/1afe45f89d54b7183768ebbbbf14238ec187ab5c","https://git.kernel.org/stable/c/b351fbe71091f7c8676c8ba597653d08b6719447","https://git.kernel.org/stable/c/5747435e0fd474c24530ef1a6822f47e7d264b27"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43292.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43292","state":"PUBLISHED","datePublished":"2026-05-08T13:11:16.017Z","dateUpdated":"2026-05-11T22:21:44.094Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.999Z"},"containers":{"cna":{"title":"mm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node\n\nWhen CONFIG_PAGE_OWNER is enabled, freeing KASAN shadow pages during\nvmalloc cleanup triggers expensive stack unwinding that acquires RCU read\nlocks.  Processing a large purge_list without rescheduling can cause the\ntask to hold CPU for extended periods (10+ seconds), leading to RCU stalls\nand potential OOM conditions.\n\nThe issue manifests in purge_vmap_node() -> kasan_release_vmalloc_node()\nwhere iterating through hundreds or thousands of vmap_area entries and\nfreeing their associated shadow pages causes:\n\n  rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:\n  rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6229/1:b..l\n  ...\n  task:kworker/0:17 state:R running task stack:28840 pid:6229\n  ...\n  kasan_release_vmalloc_node+0x1ba/0xad0 mm/vmalloc.c:2299\n  purge_vmap_node+0x1ba/0xad0 mm/vmalloc.c:2299\n\nEach call to kasan_release_vmalloc() can free many pages, and with\npage_owner tracking, each free triggers save_stack() which performs stack\nunwinding under RCU read lock.  Without yielding, this creates an\nunbounded RCU critical section.\n\nAdd periodic cond_resched() calls within the loop to allow:\n- RCU grace periods to complete\n- Other tasks to run\n- Scheduler to preempt when needed\n\nThe fix uses need_resched() for immediate response under load, with a\nbatch count of 32 as a guaranteed upper bound to prevent worst-case stalls\neven under light load."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"2efa9c02c9b4c0d6866aa445f11056809b25ca28","versionType":"git"},{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"1afe45f89d54b7183768ebbbbf14238ec187ab5c","versionType":"git"},{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"b351fbe71091f7c8676c8ba597653d08b6719447","versionType":"git"},{"version":"282631cb2447318e2a55b41a665dbe8571c46d70","status":"affected","lessThan":"5747435e0fd474c24530ef1a6822f47e7d264b27","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/vmalloc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/vmalloc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2efa9c02c9b4c0d6866aa445f11056809b25ca28"},{"url":"https://git.kernel.org/stable/c/1afe45f89d54b7183768ebbbbf14238ec187ab5c"},{"url":"https://git.kernel.org/stable/c/b351fbe71091f7c8676c8ba597653d08b6719447"},{"url":"https://git.kernel.org/stable/c/5747435e0fd474c24530ef1a6822f47e7d264b27"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:21:44.094Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}