Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_counter: serialize reset with spinlock Add a global static spinlock to serialize counter fetch+reset operations, preventing concurrent dump-and-reset from underrunning values. The lock is taken before fetching the total so that two parallel resets cannot both read the same counter values and then both subtract them. A global lock is used for simplicity since resets are infrequent. If this becomes a bottleneck, it can be replaced with a per-net lock later.

References 2

• git.kernel.org https://git.kernel.org/stable/c/0cdc6d5a26f2d1f7f15a43526841b679445c32e2
• git.kernel.org https://git.kernel.org/stable/c/779c60a5190c42689534172f4b49e927c9959e4e

Remediation