{"id":"CVE-2026-72122","summary":"can: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure","details":"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-\u003eifindex and checks bo-\u003ebound 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-\u003ebound check purely as a fast-path reject, and\nmove the ifindex read (and a bo-\u003ebound 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-\u003ebound 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.","modified":"2026-08-18T03:56:20.753901103Z","published":"2026-08-15T05:53:00.704Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72122.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0f6f9f95294b4cbb26ba02209e893e3bd91237c3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6bcc5cd247c2934373bc2a1cdf8bf12321169543"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9e60c586faeaed80d55ab8ce2a4b8e56133bc395"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b70f1a15533afeeec5d07f20bec3f3867ab1c7b6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b9c6ac6fb4e01b34575816066e5d3890a57b3c86"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d9b091d9d22fee81ec53fb55d2032951993ceadb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ffa80a2af27c97453861a5128e537214a31cd18a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72122.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72122"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ffd980f976e7fd666c2e61bf8ab35107efd11828"},{"fixed":"9e60c586faeaed80d55ab8ce2a4b8e56133bc395"},{"fixed":"ffa80a2af27c97453861a5128e537214a31cd18a"},{"fixed":"6bcc5cd247c2934373bc2a1cdf8bf12321169543"},{"fixed":"0f6f9f95294b4cbb26ba02209e893e3bd91237c3"},{"fixed":"b70f1a15533afeeec5d07f20bec3f3867ab1c7b6"},{"fixed":"35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d"},{"fixed":"b9c6ac6fb4e01b34575816066e5d3890a57b3c86"},{"fixed":"d9b091d9d22fee81ec53fb55d2032951993ceadb"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72122.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.25"},{"fixed":"5.10.261"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72122.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L"}]}