CVE-2024-43888

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

mm: list_lru: fix UAF for memory cgroup

The mem_cgroup_from_slab_obj() is supposed to be called under rcu lock or cgroup_mutex or others which could prevent returned memcg from being freed. Fix it by adding missing rcu read lock.

Found by code inspection.

[songmuchun@bytedance.com: only grab rcu lock when necessary, per Vlastimil]

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/4589f77c18dd98b65f45617b6d1e95313cf6fcab
• https://git.kernel.org/stable/c/5161b48712dcd08ec427c450399d4d1483e21dea