netfilter: ipset: fix region locking in hash types

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix region locking in hash types Region locking introduced in v5.6-rc4 contained three macros to handle the region locks: ahash_bucket_start(), ahash_bucket_end() which gave back the start and end hash bucket values belonging to a given region lock and ahash_region() which should give back the region lock belonging to a given hash bucket. The latter was incorrect which can lead to a race condition between the garbage collector and adding new elements when a hash type of set is defined with timeouts.

References

• https://git.kernel.org/stable/c/00cfc5fad1491796942a948808afb968a0a3f35b
• https://git.kernel.org/stable/c/226ce0ec38316d9e3739e73a64b6b8304646c658
• https://git.kernel.org/stable/c/82c1eb32693bc48251d92532975e19160987e5b9
• https://git.kernel.org/stable/c/aa77294b0f73bb8265987591460cd25b8722c3df
• https://git.kernel.org/stable/c/a3dfec485401943e315c394c29afe2db8f9481d6
• https://git.kernel.org/stable/c/e2ab67672b2288521a6146034a971f9a82ffc5c5
• https://git.kernel.org/stable/c/6e002ecc1c8cfdfc866b9104ab7888da54613e59
• https://git.kernel.org/stable/c/8478a729c0462273188263136880480729e9efca