CVE-2026-72119 can: bcm: extend bcm_tx_lock usage for data and timer updates
A race condition in the Linux kernel CAN BCM module allows concurrent access to unvalidated frames and torn timer reads, potentially causing system instability or crashes.
- 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-2026-72119?
CVE-2026-72119 is a high-severity vulnerability in Linux, published on 15 Aug 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:
can: bcm: extend bcm_tx_lock usage for data and timer updates
Stage new CAN frame content for an existing tx op into a kmalloc()'d buffer and validate it there, mirroring the approach already used in bcm_rx_setup(). Only copy the validated data into op->frames while holding op->bcm_tx_lock, so bcm_can_tx() and bcm_tx_timeout_handler() can no longer observe a partially updated or unvalidated frame.
Add a missing error path for memcpy_from_msg() when copying CAN frame data from userspace.
Also move the kt_ival1/kt_ival2/ival1/ival2 updates in bcm_tx_setup() under op->bcm_tx_lock, and read kt_ival1/kt_ival2/count under the same lock in bcm_tx_set_expiry() and bcm_tx_timeout_handler(), closing the torn 64-bit ktime_t read on 32-bit platforms.
Which versions are affected by CVE-2026-72119?
How do I fix CVE-2026-72119?
Apply the vendor's patch.
Is CVE-2026-72119 being exploited?
There is no known exploitation of CVE-2026-72119 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72119, DEBIAN-CVE-2026-72119, GHSA-8pfg-cf9x-g4pr, UBUNTU-CVE-2026-72119.