{"id":"CVE-2026-98418","state":"PUBLISHED","title":"sched/core: Avoid false migration warning for proxy donors","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched/core: Avoid false migration warning for proxy donors\n\nProxy execution can move a blocked donor's scheduling context to the\nlock owner's CPU even when the donor is migration-disabled. The donor\ndoes not execute there, and its original execution CPU remains recorded\nin wake_cpu.\n\nset_task_cpu() warns unconditionally for migration-disabled tasks, so a\nsubsequent proxy migration or the wakeup path returning the donor home\ntriggers a false positive: moving a blocked scheduling context does not\nviolate the migration-disabled execution context.\n\nFor example, creating a mutex owner on CPU1 and a migration-disabled\nwaiter on CPU0 can trigger the following warning:\n\n  proxy_migrate_repro: donor blocking on CPU0 with migration disabled\n  proxy_migrate_repro: donor moved from CPU0 to CPU1\n  WARNING: kernel/sched/core.c:3389 at set_task_cpu+0x1d3/0x280\n  ...\n  Call Trace:\n   try_to_wake_up+0x43f/0x780\n   __mutex_unlock_slowpath+0x330/0x540\n   owner_fn+0x9f/0xc0 [proxy_migrate_repro]\n  ...\n  proxy_migrate_repro: donor woke on CPU0, task_cpu=0\n  proxy_migrate_repro: completed\n\nExclude blocked proxy donors from the warning. The proxy wakeup path\nrestores an executable placement before clearing the blocked state.","publishedAt":"2026-10-14T13:27:48.406Z","updatedAt":"2026-10-19T09:19:11.970Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b049b81bdff6fc6794200a4c7d7d910e2008d57f","status":"affected","lessThan":"e4a442da49fff7619b3cb2988e477022dcea6688","versionType":"git"},{"version":"b049b81bdff6fc6794200a4c7d7d910e2008d57f","status":"affected","lessThan":"fe3c73d7bc769e7afc252f867a3421fe168b898d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"7.2.8","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":["kernel/sched/core.c"]}],"references":["https://git.kernel.org/stable/c/e4a442da49fff7619b3cb2988e477022dcea6688","https://git.kernel.org/stable/c/fe3c73d7bc769e7afc252f867a3421fe168b898d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98418.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98418","state":"PUBLISHED","datePublished":"2026-10-14T13:27:48.406Z","dateUpdated":"2026-10-19T09:19:11.970Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.347Z"},"containers":{"cna":{"title":"sched/core: Avoid false migration warning for proxy donors","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched/core: Avoid false migration warning for proxy donors\n\nProxy execution can move a blocked donor's scheduling context to the\nlock owner's CPU even when the donor is migration-disabled. The donor\ndoes not execute there, and its original execution CPU remains recorded\nin wake_cpu.\n\nset_task_cpu() warns unconditionally for migration-disabled tasks, so a\nsubsequent proxy migration or the wakeup path returning the donor home\ntriggers a false positive: moving a blocked scheduling context does not\nviolate the migration-disabled execution context.\n\nFor example, creating a mutex owner on CPU1 and a migration-disabled\nwaiter on CPU0 can trigger the following warning:\n\n  proxy_migrate_repro: donor blocking on CPU0 with migration disabled\n  proxy_migrate_repro: donor moved from CPU0 to CPU1\n  WARNING: kernel/sched/core.c:3389 at set_task_cpu+0x1d3/0x280\n  ...\n  Call Trace:\n   try_to_wake_up+0x43f/0x780\n   __mutex_unlock_slowpath+0x330/0x540\n   owner_fn+0x9f/0xc0 [proxy_migrate_repro]\n  ...\n  proxy_migrate_repro: donor woke on CPU0, task_cpu=0\n  proxy_migrate_repro: completed\n\nExclude blocked proxy donors from the warning. The proxy wakeup path\nrestores an executable placement before clearing the blocked state."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b049b81bdff6fc6794200a4c7d7d910e2008d57f","status":"affected","lessThan":"e4a442da49fff7619b3cb2988e477022dcea6688","versionType":"git"},{"version":"b049b81bdff6fc6794200a4c7d7d910e2008d57f","status":"affected","lessThan":"fe3c73d7bc769e7afc252f867a3421fe168b898d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"7.2.8","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":["kernel/sched/core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e4a442da49fff7619b3cb2988e477022dcea6688"},{"url":"https://git.kernel.org/stable/c/fe3c73d7bc769e7afc252f867a3421fe168b898d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:19:11.970Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.2.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}