GHSA-37FW-XV85-Q5FG
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-19 18:32In the Linux kernel, the following vulnerability has been resolved:
can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER
isotp_release() looked up the bound network device via dev_get_by_index() using the stored ifindex. During device unregistration the device is unlisted from the ifindex hash before the NETDEV_UNREGISTER notifier chain runs, so a concurrent isotp_release() could find no device, skip can_rx_unregister() entirely, and still proceed to free the socket. Since isotp_release() had already removed itself from the isotp notifier list at that point, isotp_notify() would never get a chance to clean up either, leaving a stale CAN filter that keeps pointing at the freed socket.
Fix this the same way raw.c already does: hold a tracked reference to the bound net_device in the socket (so->dev/so->dev_tracker) from bind() onward instead of re-resolving it from the ifindex, and serialize bind()/release() with rtnl_lock() so that so->dev is always consistent with what the NETDEV_UNREGISTER notifier sees. so->dev stays valid regardless of ifindex-hash unlisting, and is only ever cleared by whichever of isotp_release()/isotp_notify() gets there first, so the filter is always removed exactly once.
isotp_bind() now rejects a (re)bind with -EAGAIN while so->[tx|rx].state isn't ISOTP_IDLE yet, so a timer left running by a prior NETDEV_UNREGISTER can't act on a newly bound so->ifindex. Both checks share the same lock_sock() section, so there is no window in which a concurrent isotp_notify() clearing so->bound could be missed.
{
"affected": [],
"aliases": [
"CVE-2026-72125"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:21:29Z",
"severity": "HIGH"
},
"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\u0027t ISOTP_IDLE yet, so a timer left running by a prior\nNETDEV_UNREGISTER can\u0027t 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.",
"id": "GHSA-37fw-xv85-q5fg",
"modified": "2026-08-19T18:32:27Z",
"published": "2026-08-15T06:32:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72125"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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Nomenclature
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