SB20260626118 - Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel netfilter

Description

This security bulletin contains information about 1 vulnerability.

1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: N/A)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper state validation in nfqnl_reinject() in net/netfilter/nfnetlink_queue.c when reinjecting queued bridge packets after bridge port membership changes. A local user can remove a bridge port from the bridge while a packet is queued to cause a denial of service.

The queued skb leaves RCU protection, and the advisory notes that rx_handler_data could point to data that is not a net_bridge_port structure at reinjection time.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/43330a1e8aace6b5a8de9aba127e9e394ab49b0f
• https://git.kernel.org/stable/c/4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
• https://git.kernel.org/stable/c/ccb9fd4b87538ccf19ccff78ee26700526d94867
• https://git.kernel.org/stable/c/d4b1301fd3c9e5e105fd3767c68bc4ba558bb228