CVE-2026-89518
2026-09-11
20h19 +00:00
20h19 +00:00
Thông báo cho một CVE
Luôn được thông báo về mọi thay đổi đối với một CVE cụ thể.
Mô tả CVE
In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Fix this_rq() assumptions in dispatch kfuncs
Under core scheduling, dispatch runs from within the core-wide pick and can
target a sibling rq, so ops.dispatch() may execute on a CPU different from
the dispatched rq's. Several kfunc paths assumed the two always coincide:
- scx_dsq_move() decided whether an rq lock is held by testing this_rq()'s
rq flags and lock-danced accordingly. A dispatch for a sibling took the
unlocked-context branch and acquired the source rq lock on top of the
already held dispatched rq lock which could deadlock.
- scx_bpf_sub_dispatch() dispatched this_rq() with its stashed
sub_dispatch_prev, which is NULL when dispatching for a sibling.
- finish_dispatch(), scx_bpf_dsq_reenq() and scx_bpf_dsq_nr_queued()
resolved SCX_DSQ_LOCAL to this CPU's local DSQ rather than the dispatched
rq's. The latter two are callable from other rq-locked operations too,
where SCX_DSQ_LOCAL now likewise resolves to the op's rq. This changes
behavior also without core scheduling, e.g. for ops.enqueue() running a
remote wakeup on the waking CPU, and is intended: which CPU happens to
execute an operation is incidental, the op's rq is what it is operating
on, and the resolution now matches the insert side where SCX_DSQ_LOCAL
dispatches land on the task's rq.
Use the rq tracked by scx_locked_rq(), which is set to the dispatched rq
around ops invocations and NULL in unlocked contexts.
