CVE-2022-48643: netfilter: nf_tables: fix nft_counters_enabled underflow at nf_tables_addchain()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-28 · updated 2026-06-17
Weakness: CWE-191

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix nft_counters_enabled underflow at nf_tables_addchain() syzbot is reporting underflow of nft_counters_enabled counter at nf_tables_addchain() [1], for commit 43eb8949cfdffa76 ("netfilter: nf_tables: do not leave chain stats enabled on error") missed that nf_tables_chain_destroy() after nft_basechain_init() in the error path of nf_tables_addchain() decrements the counter because nft_basechain_init() makes nft_is_base_chain() return true by setting NFT_CHAIN_BASE flag. Increment the counter immediately after returning from nft_basechain_init().

Affected products

Linux kernel: from 5.10.140 before 5.10.146; from 5.15.64 before 5.15.71; from 5.19.6 before 5.19.12; 6.0-rc3, 6.0-rc4, 6.0-rc5, 6.0-rc6 — fixed in 5.10.146, 5.15.71, 5.19.12

How to fix

Upgrade to a fixed version: Linux kernel 5.10.146, 5.15.71, 5.19.12. Check the vendor advisory for mitigations.

References

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