{"id":"CVE-2026-98865","state":"PUBLISHED","title":"sched_ext: Don't run ops.dequeue() with a DSQ lock held","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't run ops.dequeue() with a DSQ lock held\n\nops.dequeue() is invoked with the source user DSQ's lock still held on\nthe consume and move paths (scx_consume_dispatch_q(),\nmove_task_between_dsqs()). A BPF scheduler which locks the source user\nDSQ from ops.dequeue() - e.g. by iterating it with bpf_iter_scx_dsq -\nself-deadlocks.\n\nops.dequeue() can only call the \"any\" kfuncs and none of them can lock a\nbuiltin DSQ, so the global and bypass paths can't deadlock; however,\nall DSQ locks share one lockdep class, so iterating any user DSQ from\nops.dequeue() on those paths trips the recursion check.\n\nMove the invocation after the DSQ unlock on all three paths.\nSCX_TASK_IN_CUSTODY is cleared under the lock serializing the transfer\nso that the callback is invoked exactly once.","publishedAt":"2026-10-18T15:51:26.449Z","updatedAt":"2026-10-19T09:26:59.604Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d","status":"affected","lessThan":"fe499ae9da46e297f578d4346c4c8e338c3118db","versionType":"git"},{"version":"ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d","status":"affected","lessThan":"cb86607ada73185f321baa7f9d94a08a3a40bbf5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/ext/ext.c","kernel/sched/ext/internal.h","kernel/sched/ext/sub.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"7.2.10","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/ext/ext.c","kernel/sched/ext/internal.h","kernel/sched/ext/sub.c"]}],"references":["https://git.kernel.org/stable/c/fe499ae9da46e297f578d4346c4c8e338c3118db","https://git.kernel.org/stable/c/cb86607ada73185f321baa7f9d94a08a3a40bbf5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98865.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98865","state":"PUBLISHED","datePublished":"2026-10-18T15:51:26.449Z","dateUpdated":"2026-10-19T09:26:59.604Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.377Z"},"containers":{"cna":{"title":"sched_ext: Don't run ops.dequeue() with a DSQ lock held","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Don't run ops.dequeue() with a DSQ lock held\n\nops.dequeue() is invoked with the source user DSQ's lock still held on\nthe consume and move paths (scx_consume_dispatch_q(),\nmove_task_between_dsqs()). A BPF scheduler which locks the source user\nDSQ from ops.dequeue() - e.g. by iterating it with bpf_iter_scx_dsq -\nself-deadlocks.\n\nops.dequeue() can only call the \"any\" kfuncs and none of them can lock a\nbuiltin DSQ, so the global and bypass paths can't deadlock; however,\nall DSQ locks share one lockdep class, so iterating any user DSQ from\nops.dequeue() on those paths trips the recursion check.\n\nMove the invocation after the DSQ unlock on all three paths.\nSCX_TASK_IN_CUSTODY is cleared under the lock serializing the transfer\nso that the callback is invoked exactly once."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d","status":"affected","lessThan":"fe499ae9da46e297f578d4346c4c8e338c3118db","versionType":"git"},{"version":"ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d","status":"affected","lessThan":"cb86607ada73185f321baa7f9d94a08a3a40bbf5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/ext/ext.c","kernel/sched/ext/internal.h","kernel/sched/ext/sub.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"7.2.10","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/ext/ext.c","kernel/sched/ext/internal.h","kernel/sched/ext/sub.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/fe499ae9da46e297f578d4346c4c8e338c3118db"},{"url":"https://git.kernel.org/stable/c/cb86607ada73185f321baa7f9d94a08a3a40bbf5"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:26:59.604Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}