Description
In the Linux kernel, the following vulnerability has been resolved: can: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure bcm_sendmsg() reads bo->ifindex and checks bo->bound before taking lock_sock(), while bcm_notify(), bcm_connect() and bcm_release() all mutate both fields under that same lock. Because the lockless reads and the locked writes are unordered with respect to each other, a racing bcm_notify() (device unregister) or bcm_connect() (concurrent bind on another thread sharing the socket) can make bcm_sendmsg() observe an inconsistent combination, e.g. a stale bound=1 together with the now-cleared ifindex=0, silently turning a socket bound to a specific CAN interface into one that also matches "any" interface. Keep the lockless bo->bound check purely as a fast-path reject, and move the ifindex read (and a bo->bound re-check) into the locked section, where every writer already serializes. This removes the possibility of observing the two fields torn against each other, rather than trying to fix it with more READ_ONCE()/WRITE_ONCE() pairs on two independently updated fields. Annotate the now-purely-lockless bo->bound accesses consistently across all its write sites. Also fix bcm_rx_setup() silently returning success when the target device disappears concurrently instead of reporting -ENODEV, so a broken RX op is no longer left registered as if it had succeeded.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
ffd980f976e7fd666c2e61bf8ab35107efd11828 to < 9e60c586faeaed80d55ab8ce2a4b8e56133bc395affectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < ffa80a2af27c97453861a5128e537214a31cd18aaffectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < 6bcc5cd247c2934373bc2a1cdf8bf12321169543affectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < 0f6f9f95294b4cbb26ba02209e893e3bd91237c3affectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < b70f1a15533afeeec5d07f20bec3f3867ab1c7b6affectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < 35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6daffectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < b9c6ac6fb4e01b34575816066e5d3890a57b3c86affectedffd980f976e7fd666c2e61bf8ab35107efd11828 to < d9b091d9d22fee81ec53fb55d2032951993ceadbaffected
Linux Linux
Default version status: affected
2.6.25affected0 to < 2.6.25unaffected5.10.261 to ≤ 5.10.*unaffected5.15.212 to ≤ 5.15.*unaffected6.1.178 to ≤ 6.1.*unaffected6.6.145 to ≤ 6.6.*unaffected6.12.97 to ≤ 6.12.*unaffected6.18.40 to ≤ 6.18.*unaffected7.1.5 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/9e60c586faeaed80d55ab8ce2a4b8e56133bc395 ↗
- https://git.kernel.org/stable/c/ffa80a2af27c97453861a5128e537214a31cd18a ↗
- https://git.kernel.org/stable/c/6bcc5cd247c2934373bc2a1cdf8bf12321169543 ↗
- https://git.kernel.org/stable/c/0f6f9f95294b4cbb26ba02209e893e3bd91237c3 ↗
- https://git.kernel.org/stable/c/b70f1a15533afeeec5d07f20bec3f3867ab1c7b6 ↗
- https://git.kernel.org/stable/c/35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d ↗
- https://git.kernel.org/stable/c/b9c6ac6fb4e01b34575816066e5d3890a57b3c86 ↗
- https://git.kernel.org/stable/c/d9b091d9d22fee81ec53fb55d2032951993ceadb ↗