CVE-2026-53314: padata: Put CPU offline callback in ONLINE section to allow failure

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-26 · updated 2026-07-06

Description

In the Linux kernel, the following vulnerability has been resolved: padata: Put CPU offline callback in ONLINE section to allow failure syzbot reported the following warning: DEAD callback error for CPU1 WARNING: kernel/cpu.c:1463 at _cpu_down+0x759/0x1020 kernel/cpu.c:1463, CPU#0: syz.0.1960/14614 at commit 4ae12d8bd9a8 ("Merge tag 'kbuild-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux") which tglx traced to padata_cpu_dead() given it's the only sub-CPUHP_TEARDOWN_CPU callback that returns an error. Failure isn't allowed in hotplug states before CPUHP_TEARDOWN_CPU so move the CPU offline callback to the ONLINE section where failure is possible.

Affected products

Linux kernel: from 4.19.202 before 4.20; from 5.4.22 before 5.5; from 5.5.6 before 6.1.175; from 6.2 before 6.6.141; from 6.7 before 6.12.91; from 6.13 before 6.18.33 — fixed in 4.20, 5.5, 6.1.175, 6.12.91, 6.18.33, 6.6.141

How to fix

Upgrade to a fixed version: Linux kernel 4.20, 5.5, 6.1.175, 6.12.91. Check the vendor advisory for mitigations.

References

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