CVE-2026-53334

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".

DAMONRECLAIM and DAMONLRUSORT could dereference NULL pointers if their damonctx 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):

DAMONRECLAIM allocates the damonctx object for its kdamond in its init function. damonreclaimenabledstore() wrongly assumes the allocation will always succeed once tried. If the damonctx allocation was failed, therefore, code execution reaches to damoncommitctx() while 'ctx' is NULL. As a result, it dereferences the NULL 'ctx' pointer. Avoid the NULL dereference by returning -ENOMEM if 'ctx' is NULL.