{"id":"CVE-2026-89518","revision":"4c83b388db784447bcad96940730c540","records":[{"revision":"4c83b388db784447bcad96940730c540","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89518","aliases":[],"title":"sched_ext: Fix this_rq() assumptions in dispatch kfuncs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Fix this_rq() assumptions in dispatch kfuncs\n\nUnder core scheduling, dispatch runs from within the core-wide pick and can\ntarget a sibling rq, so ops.dispatch() may execute on a CPU different from\nthe dispatched rq's. Several kfunc paths assumed the two always coincide:\n\n- scx_dsq_move() decided whether an rq lock is held by testing this_rq()'s\n  rq flags and lock-danced accordingly. A dispatch for a sibling took the\n  unlocked-context branch and acquired the source rq lock on top of the\n  already held dispatched rq lock which could deadlock.\n\n- scx_bpf_sub_dispatch() dispatched this_rq() with its stashed\n  sub_dispatch_prev, which is NULL when dispatching for a sibling.\n\n- finish_dispatch(), scx_bpf_dsq_reenq() and scx_bpf_dsq_nr_queued()\n  resolved SCX_DSQ_LOCAL to this CPU's local DSQ rather than the dispatched\n  rq's. The latter two are callable from other rq-locked operations too,\n  where SCX_DSQ_LOCAL now likewise resolves to the op's rq. This changes\n  behavior also without core scheduling, e.g. for ops.enqueue() running a\n  remote wakeup on the waking CPU, and is intended: which CPU happens to\n  execute an operation is incidental, the op's rq is what it is operating\n  on, and the resolution now matches the insert side where SCX_DSQ_LOCAL\n  dispatches land on the task's rq.\n\nUse the rq tracked by scx_locked_rq(), which is set to the dispatched rq\naround ops invocations and NULL in unlocked contexts.","state":0,"publishedAt":"2026-09-11T19:44:01.222+00:00","modifiedAt":"2026-10-19T08:48:09.565+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/sched/ext/ext.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4c95380701f58b8112f0b891de8d160e4199e19d\",\n                            \"lessThan\": \"6d1890d3c6137ab523799765ae2de62cc05f116d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4c95380701f58b8112f0b891de8d160e4199e19d\",\n                            \"lessThan\": \"3dd52416e44a70bc993adb96d2e0d71b9ea21359\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/sched/ext/ext.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.19\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.19\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/6d1890d3c6137ab523799765ae2de62cc05f116d","https://git.kernel.org/stable/c/3dd52416e44a70bc993adb96d2e0d71b9ea21359"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89518","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89518","identifiers":["CVE-2026-89518"]},"retained":false,"historicalAffected":[]}],"coverage":[]}