{"id":"CVE-2026-31734","summary":"sched_ext: Fix is_bpf_migration_disabled() false negative on non-PREEMPT_RCU","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Fix is_bpf_migration_disabled() false negative on non-PREEMPT_RCU\n\nSince commit 8e4f0b1ebcf2 (\"bpf: use rcu_read_lock_dont_migrate() for\ntrampoline.c\"), the BPF prolog (__bpf_prog_enter) calls migrate_disable()\nonly when CONFIG_PREEMPT_RCU is enabled, via rcu_read_lock_dont_migrate().\nWithout CONFIG_PREEMPT_RCU, the prolog never touches migration_disabled,\nso migration_disabled == 1 always means the task is truly\nmigration-disabled regardless of whether it is the current task.\n\nThe old unconditional p == current check was a false negative in this\ncase, potentially allowing a migration-disabled task to be dispatched to\na remote CPU and triggering scx_error in task_can_run_on_remote_rq().\n\nOnly apply the p == current disambiguation when CONFIG_PREEMPT_RCU is\nenabled, where the ambiguity with the BPF prolog still exists.","modified":"2026-07-15T01:49:13.350672211Z","published":"2026-05-01T14:14:32.217Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31734.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0c4a59df370bea245695c00aaae6ae75747139bd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/72c43eb2e334febe93018cfb68ae828f55c6e49e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b4992a9446bb9a639007bfd32bf5c5a7e30199e5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31734.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31734"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8e4f0b1ebcf2180ab594f204f01279a666dadf3b"},{"fixed":"72c43eb2e334febe93018cfb68ae828f55c6e49e"},{"fixed":"b4992a9446bb9a639007bfd32bf5c5a7e30199e5"},{"fixed":"0c4a59df370bea245695c00aaae6ae75747139bd"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31734.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.22"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31734.json"}}],"schema_version":"1.7.5"}