CVE-2025-22057: net: decrease cached dst counters in dst_release

Description

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

net: decrease cached dst counters in dst_release

Upstream fix ac888d58869b ("net: do not delay dst_entries_add() in
dst_release()") moved decrementing the dst count from dst_destroy to
dst_release to avoid accessing already freed data in case of netns
dismantle. However in case CONFIG_DST_CACHE is enabled and OvS+tunnels
are used, this fix is incomplete as the same issue will be seen for
cached dsts:

Unable to handle kernel paging request at virtual address ffff5aabf6b5c000
Call trace:
percpu_counter_add_batch+0x3c/0x160 (P)
dst_release+0xec/0x108
dst_cache_destroy+0x68/0xd8
dst_destroy+0x13c/0x168
dst_destroy_rcu+0x1c/0xb0
rcu_do_batch+0x18c/0x7d0
rcu_core+0x174/0x378
rcu_core_si+0x18/0x30

Fix this by invalidating the cache, and thus decrementing cached dst
counters, in dst_release too.

Classification

CVE ID: CVE-2025-22057

Affected Products

Vendor: Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.02% (probability of being exploited)

EPSS Percentile: 3.07% (scored less or equal to compared to others)

EPSS Date: 2025-04-20 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-22057
https://git.kernel.org/stable/c/ccc331fd5bcae131d2627d5ef099d4a1f6540aea
https://git.kernel.org/stable/c/92a5c18513117be69bc00419dd1724c1940f8fcd
https://git.kernel.org/stable/c/836415a8405c9665ae55352fc5ba865c242f5e4f
https://git.kernel.org/stable/c/e833e7ad64eb2f63867f65303be49ca30ee8819e
https://git.kernel.org/stable/c/3a0a3ff6593d670af2451ec363ccb7b18aec0c0a

Timeline