Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix is_bpf_migration_disabled() false negative on non-PREEMPT_RCU Since commit 8e4f0b1ebcf2 ("bpf: use rcu_read_lock_dont_migrate() for trampoline.c"), the BPF prolog (__bpf_prog_enter) calls migrate_disable() only when CONFIG_PREEMPT_RCU is enabled, via rcu_read_lock_dont_migrate(). Without CONFIG_PREEMPT_RCU, the prolog never touches migration_disabled, so migration_disabled == 1 always means the task is truly migration-disabled regardless of whether it is the current task. The old unconditional p == current check was a false negative in this case, potentially allowing a migration-disabled task to be dispatched to a remote CPU and triggering scx_error in task_can_run_on_remote_rq(). Only apply the p == current disambiguation when CONFIG_PREEMPT_RCU is enabled, where the ambiguity with the BPF prolog still exists.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8e4f0b1ebcf2180ab594f204f01279a666dadf3b before 72c43eb2e334febe93018cfb68ae828f55c6e49e; affected 8e4f0b1ebcf2180ab594f204f01279a666dadf3b before b4992a9446bb9a639007bfd32bf5c5a7e30199e5; affected 8e4f0b1ebcf2180ab594f204f01279a666dadf3b before 0c4a59df370bea245695c00aaae6ae75747139bd |
| Linux / Linux | affected 6.18; unaffected 0 before 6.18; unaffected 6.18.22 through 6.18.*; unaffected 6.19.12 through 6.19.*; unaffected 7.0 through * |
CWE
No CWE identifiers supplied.