CVE-2026-53334: mm/damon/reclaim: handle ctx allocation failure

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-01 · updated 2026-07-23
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/reclaim: handle ctx allocation failure Patch series "mm/damon/{reclaim,lru_sort}: handle ctx allocation failures". DAMON_RECLAIM and DAMON_LRU_SORT could dereference NULL pointers if their damon_ctx object allocations fail. The bugs are expected to happen infrequently because the allocations are arguably too small to fail on common setups. But theoretically they are possible and the consequences are bad. Fix those. The issues were discovered [1] by Sashiko. This patch (of 2): DAMON_RECLAIM allocates the damon_ctx object for its kdamond in its init function. damon_reclaim_enabled_store() wrongly assumes the allocation will always succeed once tried. If the damon_ctx allocation was failed, therefore, code execution reaches to damon_commit_ctx() while 'ctx' is NULL. As a result, it dereferences the NULL 'ctx' pointer. Avoid the NULL dereference by returning -ENOMEM if 'ctx' is NULL.

Affected products

Linux kernel: from 6.18 before 6.18.36; from 6.19 before 7.0.13; 7.1-rc1, 7.1-rc2, 7.1-rc3, 7.1-rc4, 7.1-rc5, 7.1-rc6 (+1) — fixed in 6.18.36, 7.0.13

How to fix

Upgrade to a fixed version: Linux kernel 6.18.36, 7.0.13. Check the vendor advisory for mitigations.

References

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