CVE-2024-26993: fs: sysfs: Fix reference leak in sysfs_break_active_protection()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-01 · updated 2026-10-15

Description

In the Linux kernel, the following vulnerability has been resolved: fs: sysfs: Fix reference leak in sysfs_break_active_protection() The sysfs_break_active_protection() routine has an obvious reference leak in its error path. If the call to kernfs_find_and_get() fails then kn will be NULL, so the companion sysfs_unbreak_active_protection() routine won't get called (and would only cause an access violation by trying to dereference kn->parent if it was called). As a result, the reference to kobj acquired at the start of the function will never be released. Fix the leak by adding an explicit kobject_put() call when kn is NULL.

Affected products

Linux kernel: from 3.16.62 before 3.17; from 3.18.121 before 3.19; from 4.4.154 before 4.5; from 4.9.125 before 4.10; from 4.14.68 before 4.15; from 4.18.6 before 4.19 — fixed in 3.17, 3.19, 4.10, 4.15, 4.19, 4.5

How to fix

Upgrade to a fixed version: Linux kernel 3.17, 3.19, 4.10, 4.15. Check the vendor advisory for mitigations.

References

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