In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: Dont use test_bit() in lockless RCU readers in hash types
Sashiko pointed out that there are a few lockless RCU readers using test_bit() which is a relaxed atomic operation and provides no memory barrier guarantees. Use test_bit_acquire() instead where the operation may run parallel with add/del/gc, i.e. is not one from the next cases
- protected by region lock
- in a set destroy phase
- in a new/temporary set creation phase
References
- https://git.kernel.org/stable/c/3219d74e4536658c937fd878a327257b86ce80dd
- https://git.kernel.org/stable/c/6329d3a9afe715fddda0460cfa46b496d61c2fe0
- https://git.kernel.org/stable/c/7445fe965b7d8756070a40e80f8b73348ccda1d7
- https://git.kernel.org/stable/c/c107233d2ff4fd7cef5d02f9124b99194957a710
- https://git.kernel.org/stable/c/c4d257734e91bfcdc71d41843392dd6400b5bb1b
- https://git.kernel.org/stable/c/e4b4984e28c16406ecb318444dea4a8bf47def3e