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CVE-2026-72122

HIGHCVSS 7.3/10EPSS 0.21%

Last modified

CVE-2026-72122 is a high-severity vulnerability rated 7.3/10 on the CVSS scale. 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. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.3/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

EPSS Probability
0.21%

11.6th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 9e60c586faeaed80d55ab8ce2a4b8e56133bc395; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < ffa80a2af27c97453861a5128e537214a31cd18a; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 6bcc5cd247c2934373bc2a1cdf8bf12321169543; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 0f6f9f95294b4cbb26ba02209e893e3bd91237c3; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < b70f1a15533afeeec5d07f20bec3f3867ab1c7b6; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < 35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < b9c6ac6fb4e01b34575816066e5d3890a57b3c86; >= ffd980f976e7fd666c2e61bf8ab35107efd11828, < d9b091d9d22fee81ec53fb55d2032951993ceadb
LinuxLinux2.6.25

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-72122?
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.
How severe is CVE-2026-72122?
CVE-2026-72122 has a CVSS score of 7.3/10 (HIGH severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-72122?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST