{"id":"CVE-2026-89519","state":"PUBLISHED","title":"sched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return\n\nSCX_RQ_BAL_KEEP tells the pick to keep running the previous task, a leftover\nfrom when balancing and picking were separate operations. An rq-level flag\nonly works while dispatches and picks pair up one to one, which core\nscheduling breaks: selections interleave through dispatch's lock drops and a\npick can consume a stale flag, keeping a task that has since been dequeued.\nFixing core scheduling support requires the decision to travel with the\ndispatch that made it. Make scx_dispatch_sched() and balance_one() return an\nexplicit verdict instead and drop the flag's plumbing from the tools autogen\nenum headers.\n\nAlso factor the pick-side invocation, its follow-up queueing and the\npost-dispatch checks out of do_pick_task_scx() into dispatch_pick(). No\nfunctional changes intended.\n\nv2: Drop the SCX_RQ_BAL_KEEP plumbing from the tools autogen enum headers\n    as well (Andrea).","publishedAt":"2026-09-11T19:44:01.858Z","updatedAt":"2026-10-19T08:48:10.533Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4c95380701f58b8112f0b891de8d160e4199e19d","status":"affected","lessThan":"6f1d3bfe54430f8d54e0530a27f2ecbf8466576e","versionType":"git"},{"version":"4c95380701f58b8112f0b891de8d160e4199e19d","status":"affected","lessThan":"ffaab58d217581cb75353168f8812a16e10463fc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/ext/ext.c","kernel/sched/sched.h","tools/sched_ext/include/scx/enum_defs.autogen.h","tools/sched_ext/include/scx/enums.autogen.bpf.h","tools/sched_ext/include/scx/enums.autogen.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.2.4","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/sched.h","tools/sched_ext/include/scx/enum_defs.autogen.h","tools/sched_ext/include/scx/enums.autogen.bpf.h","tools/sched_ext/include/scx/enums.autogen.h"]}],"references":["https://git.kernel.org/stable/c/6f1d3bfe54430f8d54e0530a27f2ecbf8466576e","https://git.kernel.org/stable/c/ffaab58d217581cb75353168f8812a16e10463fc"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89519.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89519","state":"PUBLISHED","datePublished":"2026-09-11T19:44:01.858Z","dateUpdated":"2026-10-19T08:48:10.533Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.718Z"},"containers":{"cna":{"title":"sched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return\n\nSCX_RQ_BAL_KEEP tells the pick to keep running the previous task, a leftover\nfrom when balancing and picking were separate operations. An rq-level flag\nonly works while dispatches and picks pair up one to one, which core\nscheduling breaks: selections interleave through dispatch's lock drops and a\npick can consume a stale flag, keeping a task that has since been dequeued.\nFixing core scheduling support requires the decision to travel with the\ndispatch that made it. Make scx_dispatch_sched() and balance_one() return an\nexplicit verdict instead and drop the flag's plumbing from the tools autogen\nenum headers.\n\nAlso factor the pick-side invocation, its follow-up queueing and the\npost-dispatch checks out of do_pick_task_scx() into dispatch_pick(). No\nfunctional changes intended.\n\nv2: Drop the SCX_RQ_BAL_KEEP plumbing from the tools autogen enum headers\n    as well (Andrea)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4c95380701f58b8112f0b891de8d160e4199e19d","status":"affected","lessThan":"6f1d3bfe54430f8d54e0530a27f2ecbf8466576e","versionType":"git"},{"version":"4c95380701f58b8112f0b891de8d160e4199e19d","status":"affected","lessThan":"ffaab58d217581cb75353168f8812a16e10463fc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/ext/ext.c","kernel/sched/sched.h","tools/sched_ext/include/scx/enum_defs.autogen.h","tools/sched_ext/include/scx/enums.autogen.bpf.h","tools/sched_ext/include/scx/enums.autogen.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.2.4","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/sched.h","tools/sched_ext/include/scx/enum_defs.autogen.h","tools/sched_ext/include/scx/enums.autogen.bpf.h","tools/sched_ext/include/scx/enums.autogen.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/6f1d3bfe54430f8d54e0530a27f2ecbf8466576e"},{"url":"https://git.kernel.org/stable/c/ffaab58d217581cb75353168f8812a16e10463fc"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:48:10.533Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}