Description
In the Linux kernel, the following vulnerability has been resolved:

sched/core: Avoid false migration warning for proxy donors

Proxy execution can move a blocked donor's scheduling context to the
lock owner's CPU even when the donor is migration-disabled. The donor
does not execute there, and its original execution CPU remains recorded
in wake_cpu.

set_task_cpu() warns unconditionally for migration-disabled tasks, so a
subsequent proxy migration or the wakeup path returning the donor home
triggers a false positive: moving a blocked scheduling context does not
violate the migration-disabled execution context.

For example, creating a mutex owner on CPU1 and a migration-disabled
waiter on CPU0 can trigger the following warning:

proxy_migrate_repro: donor blocking on CPU0 with migration disabled
proxy_migrate_repro: donor moved from CPU0 to CPU1
WARNING: kernel/sched/core.c:3389 at set_task_cpu+0x1d3/0x280
...
Call Trace:
try_to_wake_up+0x43f/0x780
__mutex_unlock_slowpath+0x330/0x540
owner_fn+0x9f/0xc0 [proxy_migrate_repro]
...
proxy_migrate_repro: donor woke on CPU0, task_cpu=0
proxy_migrate_repro: completed

Exclude blocked proxy donors from the warning. The proxy wakeup path
restores an executable placement before clearing the blocked state.
Published: 2026-10-14
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Wed, 14 Oct 2026 13:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: sched/core: Avoid false migration warning for proxy donors Proxy execution can move a blocked donor's scheduling context to the lock owner's CPU even when the donor is migration-disabled. The donor does not execute there, and its original execution CPU remains recorded in wake_cpu. set_task_cpu() warns unconditionally for migration-disabled tasks, so a subsequent proxy migration or the wakeup path returning the donor home triggers a false positive: moving a blocked scheduling context does not violate the migration-disabled execution context. For example, creating a mutex owner on CPU1 and a migration-disabled waiter on CPU0 can trigger the following warning: proxy_migrate_repro: donor blocking on CPU0 with migration disabled proxy_migrate_repro: donor moved from CPU0 to CPU1 WARNING: kernel/sched/core.c:3389 at set_task_cpu+0x1d3/0x280 ... Call Trace: try_to_wake_up+0x43f/0x780 __mutex_unlock_slowpath+0x330/0x540 owner_fn+0x9f/0xc0 [proxy_migrate_repro] ... proxy_migrate_repro: donor woke on CPU0, task_cpu=0 proxy_migrate_repro: completed Exclude blocked proxy donors from the warning. The proxy wakeup path restores an executable placement before clearing the blocked state.
Title sched/core: Avoid false migration warning for proxy donors
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-14T13:27:48.406Z

Reserved: 2026-09-25T10:25:14.347Z

Link: CVE-2026-98418

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-14T14:17:53.173

Modified: 2026-10-14T14:17:53.173

Link: CVE-2026-98418

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses

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