Bug 2532093 (CVE-2026-89516) - CVE-2026-89516 kernel: sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users
Summary: CVE-2026-89516 kernel: sched_ext: Don't BUG_ON a destroyed DSQ in process_def...
Keywords:
Status: NEW
Alias: CVE-2026-89516
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-11 20:29 UTC by OSIDB Bzimport
Modified: 2026-09-18 12:47 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-09-11 20:29:15 UTC
In the Linux kernel, the following vulnerability has been resolved:

sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users

scx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from
run_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru
runs, process_deferred_reenq_users() sees dsq->id == SCX_DSQ_INVALID and
hits the BUG_ON. destroy_dsq() doesn't flush pending drus, so just skip.

tj: Read dsq->id once with READ_ONCE(). Reading it separately in the INVALID
    check and the BUG_ON would leave a window where destroy_dsq() can
    invalidate the id between the two reads and still trigger the BUG_ON.


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