CVE-2026-97963 net: stmmac: initialize ptp_lock at probe time
An uninitialized lock in the stmmac network driver can cause a kernel crash when configuring TAPRIO schedules on a down interface.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97963?
CVE-2026-97963 is a vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: initialize ptp_lock at probe time
priv->ptp_lock is only initialized in stmmac_ptp_register(), which runs during __stmmac_open(). However, the lock is also used while the interface is down and has never been opened: tc_taprio_configure() invokes the PTP gettime64() callback to compute the EST base time when offloading a TAPRIO schedule, and stmmac_get_time() takes priv->ptp_lock. Using an uninitialized rwlock is undefined behaviour. Move the rwlock_init() to __stmmac_dvr_probe(), together with the other private locks, so that ptp_lock is always valid regardless of the interface state.
Which versions are affected by CVE-2026-97963?
How do I fix CVE-2026-97963?
Apply the vendor's patch.
Is CVE-2026-97963 being exploited?
There is no known exploitation of CVE-2026-97963 in the wild and no public exploit code.
Sources
Also known as AZL-104268, BELL-CVE-2026-97963, DEBIAN-CVE-2026-97963, GHSA-rqgr-p8xr-jcx7, UBUNTU-CVE-2026-97963.