{"id":"CVE-2026-72125","summary":"can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER\n\nisotp_release() looked up the bound network device via dev_get_by_index()\nusing the stored ifindex. During device unregistration the device is\nunlisted from the ifindex hash before the NETDEV_UNREGISTER notifier\nchain runs, so a concurrent isotp_release() could find no device, skip\ncan_rx_unregister() entirely, and still proceed to free the socket.\nSince isotp_release() had already removed itself from the isotp\nnotifier list at that point, isotp_notify() would never get a chance to\nclean up either, leaving a stale CAN filter that keeps pointing at the\nfreed socket.\n\nFix this the same way raw.c already does: hold a tracked reference to\nthe bound net_device in the socket (so-\u003edev/so-\u003edev_tracker) from\nbind() onward instead of re-resolving it from the ifindex, and\nserialize bind()/release() with rtnl_lock() so that so-\u003edev is always\nconsistent with what the NETDEV_UNREGISTER notifier sees. so-\u003edev\nstays valid regardless of ifindex-hash unlisting, and is only ever\ncleared by whichever of isotp_release()/isotp_notify() gets there\nfirst, so the filter is always removed exactly once.\n\nisotp_bind() now rejects a (re)bind with -EAGAIN while so-\u003e[tx|rx].state\nisn't ISOTP_IDLE yet, so a timer left running by a prior\nNETDEV_UNREGISTER can't act on a newly bound so-\u003eifindex. Both checks\nshare the same lock_sock() section, so there is no window in which a\nconcurrent isotp_notify() clearing so-\u003ebound could be missed.","modified":"2026-08-21T03:30:20.267805449Z","published":"2026-08-15T05:53:02.905Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72125.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96"},{"type":"WEB","url":"https://git.kernel.org/stable/c/20bab8b88baac140ca3701116e1d486c7f51e311"},{"type":"WEB","url":"https://git.kernel.org/stable/c/33b9cd9245e2a4b800f99ed1cc53d64960614152"},{"type":"WEB","url":"https://git.kernel.org/stable/c/43884dc7963beef2328f507f4fe680bdc173eb80"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7bef39ba76eb7307ed22a50329e0f5776dbeda58"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8e018f4335590460ebcf0c2b493ed38ba1a35204"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e442b62ba5a7756c17e05a77b32cdd085a2b6138"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f311bbb29bb06aaab69ba45a6e4b11323d20b8f9"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72125.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72125"},{"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":"e057dd3fc20ffb3d7f150af46542a51b59b90127"},{"fixed":"f311bbb29bb06aaab69ba45a6e4b11323d20b8f9"},{"fixed":"8e018f4335590460ebcf0c2b493ed38ba1a35204"},{"fixed":"33b9cd9245e2a4b800f99ed1cc53d64960614152"},{"fixed":"0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96"},{"fixed":"43884dc7963beef2328f507f4fe680bdc173eb80"},{"fixed":"7bef39ba76eb7307ed22a50329e0f5776dbeda58"},{"fixed":"e442b62ba5a7756c17e05a77b32cdd085a2b6138"},{"fixed":"20bab8b88baac140ca3701116e1d486c7f51e311"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72125.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.10.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"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-2026-72125.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:H"}]}