CVE-2026-31459: mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() 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: 2026-04-22 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() failure Patch series "mm/damon/sysfs: fix memory leak and NULL dereference issues", v4. DAMON_SYSFS can leak memory under allocation failure, and do NULL pointer dereference when a privileged user make wrong sequences of control. Fix those. This patch (of 3): When damon_sysfs_new_test_ctx() fails in damon_sysfs_commit_input(), param_ctx is leaked because the early return skips the cleanup at the out label. Destroy param_ctx before returning.

Affected products

Linux kernel: from 6.18.1 before 6.18.21; from 6.19 before 6.19.11; 6.17.6, 6.18, 6.18-rc3, 6.18-rc4, 6.18-rc5, 6.18-rc6 (+6) — fixed in 6.18.21, 6.19.11

How to fix

Upgrade to a fixed version: Linux kernel 6.18.21, 6.19.11. Check the vendor advisory for mitigations.

References

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