CVE-2026-72113
Published: August 18, 2026Last modified: August 18, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: can: bcm: add missing device refcount for CAN filter removal sashiko-bot remarked a problem with a concurrent device unregistration in isotp.c which also is present in the bcm.c code. A former fix for raw.c commit c275a176e4b6 ("can: raw: add missing refcount for memory leak fix") introduced a netdevice_tracker which solves the issue for bcm.c too. bcm_release(), bcm_delete_rx_op() and bcm_notifier() relied on dev_get_by_index(ifindex) to re-find the device for an rx_op before unregistering its filter. If a concurrent NETDEV_UNREGISTER has already unlisted the device from the ifindex table, that lookup fails and can_rx_unregister() is silently skipped, leaving a stale CAN filter pointing at the soon-to-be-freed bcm_op/socket. Hold a netdev_hold()/netdev_put() tracked reference on op->rx_reg_dev from the moment the rx filter is registered in bcm_rx_setup() until it is unregistered in bcm_rx_unreg(), and use that reference directly in bcm_release() and bcm_delete_rx_op() instead of re-looking the device up by ifindex.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Vulnerable (6.1.182-r0) |
| 25 LTS | linux-lts | Fixed (6.12.103-r0) | |
| Stream | linux-lts | Fixed (6.18.43-r0) |
References
- https://git.kernel.org/stable/c/04d23061bbf18d5d81022eb21e9d32e99d24468d
- https://git.kernel.org/stable/c/633bda66fbf309f5de5e1ad6defe8e6b1d77a20f
- https://git.kernel.org/stable/c/84aa4807816e405c1bf87114fc63e06d244281ef
- https://git.kernel.org/stable/c/b024c21c9066f6957b7d4a8f2037e4b000c5e041
- https://git.kernel.org/stable/c/bd5232663524e94cc5aad861dca11e3db8e2ab6f
- https://git.kernel.org/stable/c/d59948293ea34b6337ce2b5febab8510de70048c
- https://git.kernel.org/stable/c/dcaee869913c7210cd47ed0a8f27349d7bdcdb7b
- https://git.kernel.org/stable/c/ee8b36d0faca08f35b889b6e9aa850695e5b8ba9