SB20260928231 - Improper control of a resource through its lifetime in Linux kernel net ppp driver

Description

This security bulletin contains information about 1 vulnerability.

1) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-97964)

CWE-ID: CWE-664 - Improper control of a resource through its lifetime

CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to modify data visible to an AF_PACKET socket.

The vulnerability exists due to failure to ensure a writable skb header in ppp_sync_txmunge() when bridging a received PPP frame to a synchronous tty channel. A remote attacker can send a PPPoE frame that is bridged to a synchronous tty channel to modify data visible to an AF_PACKET socket.

Exploitation requires the frame buffer to be shared with a clone queued to an AF_PACKET socket.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0996c3e6bcc6ae08cb371ed43648c9f7f748ae6e
• https://git.kernel.org/stable/c/15d0a6c9a42df2d745c37510dba828f6dbe60d9f
• https://git.kernel.org/stable/c/3af7797fbabc84992e0ca5ad2bc0ca8537d053ef
• https://git.kernel.org/stable/c/8aaeb56aff2a557a88f83ae866da2c91ad247e59