{"id":"CVE-2026-72122","title":"can: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure\n\nbcm_sendmsg() reads bo->ifindex and checks bo->bound before taking\nlock_sock(), while bcm_notify(…","severity":"high","cvss":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 9e60c586faeaed80d55ab8ce2a4b8e56133bc395","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < ffa80a2af27c97453861a5128e537214a31cd18a","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 6bcc5cd247c2934373bc2a1cdf8bf12321169543","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 0f6f9f95294b4cbb26ba02209e893e3bd91237c3","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < b70f1a15533afeeec5d07f20bec3f3867ab1c7b6","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < b9c6ac6fb4e01b34575816066e5d3890a57b3c86","Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < d9b091d9d22fee81ec53fb55d2032951993ceadb","Linux 2.6.25"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:42:08.458786Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:44:57.450Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72122","references":[{"url":"https://git.kernel.org/stable/c/9e60c586faeaed80d55ab8ce2a4b8e56133bc395"},{"url":"https://git.kernel.org/stable/c/ffa80a2af27c97453861a5128e537214a31cd18a"},{"url":"https://git.kernel.org/stable/c/6bcc5cd247c2934373bc2a1cdf8bf12321169543"},{"url":"https://git.kernel.org/stable/c/0f6f9f95294b4cbb26ba02209e893e3bd91237c3"},{"url":"https://git.kernel.org/stable/c/b70f1a15533afeeec5d07f20bec3f3867ab1c7b6"},{"url":"https://git.kernel.org/stable/c/35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d"},{"url":"https://git.kernel.org/stable/c/b9c6ac6fb4e01b34575816066e5d3890a57b3c86"},{"url":"https://git.kernel.org/stable/c/d9b091d9d22fee81ec53fb55d2032951993ceadb"}],"tags":["cve.org"],"epss":0.00164,"epssPercentile":0.05275,"ingestedAt":"2026-10-16T19:46:24.429Z","slug":"CVE-2026-72122","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure\n\nbcm_sendmsg() reads bo->ifindex and checks bo->bound before taking\nlock_sock(), while bcm_notify(), bcm_connect() and bcm_release() all\nmutate both fields under that same lock. Because the lockless reads\nand the locked writes are unordered with respect to each other, a\nracing bcm_notify() (device unregister) or bcm_connect() (concurrent\nbind on another thread sharing the socket) can make bcm_sendmsg()\nobserve an inconsistent combination, e.g. a stale bound=1 together\nwith the now-cleared ifindex=0, silently turning a socket bound to a\nspecific CAN interface into one that also matches \"any\" interface.\n\nKeep the lockless bo->bound check purely as a fast-path reject, and\nmove the ifindex read (and a bo->bound re-check) into the locked\nsection, where every writer already serializes. This removes the\npossibility of observing the two fields torn against each other,\nrather than trying to fix it with more READ_ONCE()/WRITE_ONCE() pairs\non two independently updated fields. Annotate the now-purely-lockless\nbo->bound accesses consistently across all its write sites.\n\nAlso fix bcm_rx_setup() silently returning success when the target\ndevice disappears concurrently instead of reporting -ENODEV, so a\nbroken RX op is no longer left registered as if it had succeeded.\n\n## Affected\n\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 9e60c586faeaed80d55ab8ce2a4b8e56133bc395`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < ffa80a2af27c97453861a5128e537214a31cd18a`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 6bcc5cd247c2934373bc2a1cdf8bf12321169543`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 0f6f9f95294b4cbb26ba02209e893e3bd91237c3`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < b70f1a15533afeeec5d07f20bec3f3867ab1c7b6`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < b9c6ac6fb4e01b34575816066e5d3890a57b3c86`\n- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < d9b091d9d22fee81ec53fb55d2032951993ceadb`\n- `Linux 2.6.25`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":40.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}