GHSA-R952-5653-4WQ2
Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31In the Linux kernel, the following vulnerability has been resolved:
can: isotp: fix timer drain order, wakeup handling and tx_gen ordering
This patch is a follow-up to commit cf070fe33bfb ("can: isotp: serialize TX state transitions under so->rx_lock") which addresses following sashiko-bot findings:
-
isotp_sendmsg(): drain so->txfrtimer first so a stale callback can't re-arm echotimer after the claim
-
isotp_release(): wake so->wait after forcing ISOTP_SHUTDOWN so a sleeping sendmsg() claim isn't stranded
-
isotp_sendmsg(): have both wait_event_interruptible() calls in isotp_sendmsg() also wake on ISOTP_SHUTDOWN and do not return claim to IDLE to avoid corrupting a concurrent isotp_release() process.
-
isotp_sendmsg(): handle potential claim of a new transfer when the wait_event_interruptible() call returns in CAN_ISOTP_WAIT_TX_DONE mode. Don't touch timers and states of the new transfer if a new thread incremented so->tx_gen before getting the lock at err_event_drop.
-
isotp_sendmsg(): handle a stuck can_send() and omit timer and state changes if a new transfer was claimed. wait_tx_done() returns the error recorded in so->tx_result[], tagged with the caller's own generation.
-
isotp_tx_timeout(): on a claimed timeout, record the ECOMM error for the timed-out transfer's own generation in so->tx_result[]; sk->sk_err is raised unconditionally, same as every other error path here.
-
isotp_tx_gen_done()/isotp_tx_timeout(): always read tx.state (acquire) before tx_gen - the reverse order let a weakly ordered CPU pair a fresh tx.state with a stale tx_gen/tx_result slot.
-
isotp_sendmsg(): wait_tx_done: drain sk_err via sock_error() once we have read the result from so->tx_result[], so an already-reported error doesn't stay latched for a later poll()/SO_ERROR.
Also align the remaining lock-free so->tx.state/rx.state/cfecho accesses and use skb->hash as unique loopback echo frame indicator.
{
"affected": [],
"aliases": [
"CVE-2026-80889"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-04T18:17:56Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: isotp: fix timer drain order, wakeup handling and tx_gen ordering\n\nThis patch is a follow-up to commit cf070fe33bfb (\"can: isotp: serialize\nTX state transitions under so-\u003erx_lock\") which addresses following\nsashiko-bot findings:\n\n- isotp_sendmsg(): drain so-\u003etxfrtimer first so a stale callback can\u0027t\n re-arm echotimer after the claim\n\n- isotp_release(): wake so-\u003ewait after forcing ISOTP_SHUTDOWN so a\n sleeping sendmsg() claim isn\u0027t stranded\n\n- isotp_sendmsg(): have both wait_event_interruptible() calls in\n isotp_sendmsg() also wake on ISOTP_SHUTDOWN and do not return claim to\n IDLE to avoid corrupting a concurrent isotp_release() process.\n\n- isotp_sendmsg(): handle potential claim of a new transfer when\n the wait_event_interruptible() call returns in CAN_ISOTP_WAIT_TX_DONE\n mode. Don\u0027t touch timers and states of the new transfer if a new thread\n incremented so-\u003etx_gen before getting the lock at err_event_drop.\n\n- isotp_sendmsg(): handle a stuck can_send() and omit timer and state\n changes if a new transfer was claimed. wait_tx_done() returns the error\n recorded in so-\u003etx_result[], tagged with the caller\u0027s own generation.\n\n- isotp_tx_timeout(): on a claimed timeout, record the ECOMM error for\n the timed-out transfer\u0027s own generation in so-\u003etx_result[]; sk-\u003esk_err\n is raised unconditionally, same as every other error path here.\n\n- isotp_tx_gen_done()/isotp_tx_timeout(): always read tx.state (acquire)\n before tx_gen - the reverse order let a weakly ordered CPU pair a fresh\n tx.state with a stale tx_gen/tx_result slot.\n\n- isotp_sendmsg(): wait_tx_done: drain sk_err via sock_error() once we\n have read the result from so-\u003etx_result[], so an already-reported error\n doesn\u0027t stay latched for a later poll()/SO_ERROR.\n\nAlso align the remaining lock-free so-\u003etx.state/rx.state/cfecho accesses\nand use skb-\u003ehash as unique loopback echo frame indicator.",
"id": "GHSA-r952-5653-4wq2",
"modified": "2026-09-04T18:31:33Z",
"published": "2026-09-04T18:31:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80889"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/050f010f920da17c1044a4f174766ad553e770b6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/10be509fa8fd95d1e47d40d1f68b0b26dfe9d572"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2753722612d8824d3910096f93059f669009b0f0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/35c62ac98d06669aa3f0f38b7829eaca929a611e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8acab9fc66d6f426c36968c91a979f70784945a7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/af7e25c649ed68cbad07f8185af0f31b892cbf29"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bf5c4a8b24acb12739ebb9aea5510b007e4f5239"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/deca7746b57d982cd4f0301f4443f56780c4a048"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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