CVE-2026-80779

A flaw was found in the net/ionic component of the Linux kernel. This out-of-bounds write vulnerability occurs because the dedicated hardware timestamp RX queue's index can be used to access memory beyond the bounds of the normal transmit queue array. An attacker could potentially exploit this to cause memory corruption, leading to system instability or other undefined behavior.

The ionic driver can perform an out of bounds TX queue partner lookup when initializing the dedicated hardware timestamp RX queue. The hwstamp RX queue uses an index equal to the number of normal RX queues, while the txqcqs array only contains normal TX queue pairs, so the old code could read one element past txqcqs and then write through the derived queue pointer. For the CVSS the PR:L is used in the paranoid score because a non root local actor with delegated network administration, a service account, or container root controlling the device may be able to trigger queue reconfiguration or reset paths. The issue is not directly network reachable because packet traffic alone does not configure the RXQ partner relationship. Impact is at least denial of service and plausibly memory corruption with confidentiality and integrity risk, so this should be reviewed manually.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.