PT-2026-27684 · Linux · Linux Kernel
Published
2026-01-01
·
Updated
2026-05-22
·
CVE-2026-23319
CVSS v3.1
7.8
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The Linux kernel contains a use-after-free issue in the
bpf trampoline link cgroup shim function. The root cause is a race condition where a resource is released but may still be referenced, leading to a use-after-free condition if accessed by another process. Specifically, when bpf link put reduces the refcount of shim link->link.link to zero, the resource is considered released, but it may still be referenced via tr->progs hlist in cgroup shim find. The fix involves adding an atomic non-zero check in bpf trampoline link cgroup shim to only increment the refcount if it is not already zero. Testing involved adding a delay in bpf shim tramp link release to make the bug easier to trigger, which reliably reproduced the crash before the patch.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Linux Kernel