CVE-2023-54033

Summary

In the Linux kernel, the following vulnerability has been resolved:

bpf: fix a memory leak in the LRU and LRU_PERCPU hash maps

The LRU and LRU_PERCPU maps allocate a new element on update before locking the target hash table bucket. Right after that the maps try to lock the bucket. If this fails, then maps return -EBUSY to the caller without releasing the allocated element. This makes the element untracked: it doesn't belong to either of free lists, and it doesn't belong to the hash table, so can't be re-used; this eventually leads to the permanent -ENOMEM on LRU map updates, which is unexpected. Fix this by returning the element to the local free list if bucket locking fails.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux20b6cc34ea74b6a84599c1f8a70f3315b56a1883 < 79ea1a12fb9a8275b6e19d4ca625dd872dedcbb9affected
LinuxLinux20b6cc34ea74b6a84599c1f8a70f3315b56a1883 < 1a9e80f757bbb1562d82e350afce2bb2f712cc3daffected
LinuxLinux20b6cc34ea74b6a84599c1f8a70f3315b56a1883 < 965e9cccbe6b9c7b379908cebcb5e3a47f20dd5eaffected
LinuxLinux20b6cc34ea74b6a84599c1f8a70f3315b56a1883 < b34ffb0c6d23583830f9327864b9c1f486003305affected
LinuxLinux5.11affected
LinuxLinux0 < 5.11unaffected
LinuxLinux5.15.115 <= 5.15.*unaffected
LinuxLinux6.1.31 <= 6.1.*unaffected
LinuxLinux6.3.5 <= 6.3.*unaffected
LinuxLinux6.4 <= *unaffected

Weaknesses

References