CVE-2026-23362: can: bcm: fix locking for bcm_op runtime updates

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-25 · updated 2026-06-17
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: can: bcm: fix locking for bcm_op runtime updates Commit c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates") added a locking for some variables that can be modified at runtime when updating the sending bcm_op with a new TX_SETUP command in bcm_tx_setup(). Usually the RX_SETUP only handles and filters incoming traffic with one exception: When the RX_RTR_FRAME flag is set a predefined CAN frame is sent when a specific RTR frame is received. Therefore the rx bcm_op uses bcm_can_tx() which uses the bcm_tx_lock that was only initialized in bcm_tx_setup(). Add the missing spin_lock_init() when allocating the bcm_op in bcm_rx_setup() to handle the RTR case properly.

Affected products

Linux kernel: from 5.4.294 before 5.5; from 5.10.238 before 5.10.253; from 5.15.185 before 5.15.203; from 6.1.141 before 6.1.167; from 6.6.93 before 6.6.130; from 6.12.31 before 6.12.77 — fixed in 5.10.253, 5.15.203, 5.5, 6.1.167, 6.12.77, 6.15

How to fix

Upgrade to a fixed version: Linux kernel 5.10.253, 5.15.203, 5.5, 6.1.167. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-23362 or the next vulnerability affects your stack