{"id":"CVE-2026-72125","title":"can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER","summary":"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 ifinde…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < f311bbb29bb06aaab69ba45a6e4b11323d20b8f9","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 8e018f4335590460ebcf0c2b493ed38ba1a35204","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 33b9cd9245e2a4b800f99ed1cc53d64960614152","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 43884dc7963beef2328f507f4fe680bdc173eb80","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 7bef39ba76eb7307ed22a50329e0f5776dbeda58","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < e442b62ba5a7756c17e05a77b32cdd085a2b6138","Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 20bab8b88baac140ca3701116e1d486c7f51e311","Linux 5.10"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:42:17.799188Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:44:57.938Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72125","references":[{"url":"https://git.kernel.org/stable/c/f311bbb29bb06aaab69ba45a6e4b11323d20b8f9"},{"url":"https://git.kernel.org/stable/c/8e018f4335590460ebcf0c2b493ed38ba1a35204"},{"url":"https://git.kernel.org/stable/c/33b9cd9245e2a4b800f99ed1cc53d64960614152"},{"url":"https://git.kernel.org/stable/c/0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96"},{"url":"https://git.kernel.org/stable/c/43884dc7963beef2328f507f4fe680bdc173eb80"},{"url":"https://git.kernel.org/stable/c/7bef39ba76eb7307ed22a50329e0f5776dbeda58"},{"url":"https://git.kernel.org/stable/c/e442b62ba5a7756c17e05a77b32cdd085a2b6138"},{"url":"https://git.kernel.org/stable/c/20bab8b88baac140ca3701116e1d486c7f51e311"}],"tags":["cve.org"],"epss":0.00164,"epssPercentile":0.05239,"ingestedAt":"2026-10-16T19:46:24.429Z","slug":"CVE-2026-72125","body":"## Overview\n\nIn 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->dev/so->dev_tracker) from\nbind() onward instead of re-resolving it from the ifindex, and\nserialize bind()/release() with rtnl_lock() so that so->dev is always\nconsistent with what the NETDEV_UNREGISTER notifier sees. so->dev\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->[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->ifindex. Both checks\nshare the same lock_sock() section, so there is no window in which a\nconcurrent isotp_notify() clearing so->bound could be missed.\n\n## Affected\n\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < f311bbb29bb06aaab69ba45a6e4b11323d20b8f9`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 8e018f4335590460ebcf0c2b493ed38ba1a35204`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 33b9cd9245e2a4b800f99ed1cc53d64960614152`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 43884dc7963beef2328f507f4fe680bdc173eb80`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 7bef39ba76eb7307ed22a50329e0f5776dbeda58`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < e442b62ba5a7756c17e05a77b32cdd085a2b6138`\n- `Linux >= e057dd3fc20ffb3d7f150af46542a51b59b90127 < 20bab8b88baac140ca3701116e1d486c7f51e311`\n- `Linux 5.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}