CVE-2026-53314 padata: Put CPU offline callback in ONLINE section to allow failure
A kernel bug in the padata subsystem causes a warning and potential crash during CPU offline operations, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53314?
CVE-2026-53314 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-53314?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53314?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-53314 being exploited?
There is no known exploitation of CVE-2026-53314 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53314, DEBIAN-CVE-2026-53314, GHSA-4fpm-3x7p-95xm, ROOT-OS-DEBIAN-11-CVE-2026-53314, ROOT-OS-UBUNTU-2204-CVE-2026-53314, ROOT-OS-UBUNTU-2404-CVE-2026-53314 and 1 more.