SB20261022418 - Integer underflow in Linux kernel stmicro stmmac driver

Description

This security bulletin contains information about 1 vulnerability.

1) Integer underflow (CVE-ID: CVE-2026-98803)

CWE-ID: CWE-191 - Integer underflow

CVSSv4: 5.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker on the local network to corrupt receive-buffer length calculations, potentially causing a denial of service.

The vulnerability exists due to an unsigned integer underflow in stmmac frame check sequence removal when a received frame overflows a buffer by one to three bytes. A remote attacker on the local network can send a frame whose frame check sequence straddles receive-buffer boundaries to make subtraction of the frame check sequence length wrap to an excessively large unsigned value, potentially disrupting packet processing.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/358d5ac5a5d57ce21c3814c4e3e8f3fbcb7304b4
• https://git.kernel.org/stable/c/88095728511e0df9c89528944f5a1762ad298983
• https://git.kernel.org/stable/c/a7cff44543f66f3a19151060cb549691d191d44c