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.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HAffected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < bd5232663524e94cc5aad861dca11e3db8e2ab6f; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < ee8b36d0faca08f35b889b6e9aa850695e5b8ba9; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < dcaee869913c7210cd47ed0a8f27349d7bdcdb7b; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 84aa4807816e405c1bf87114fc63e06d244281ef; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 633bda66fbf309f5de5e1ad6defe8e6b1d77a20f; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < b024c21c9066f6957b7d4a8f2037e4b000c5e041; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 04d23061bbf18d5d81022eb21e9d32e99d24468d; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < d59948293ea34b6337ce2b5febab8510de70048c |
| Linux | Linux | 2.6.25 |
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
Timeline
- Published
- Aug 15, 2026
- Last modified
- Oct 16, 2026
- NVD status
- Received