CVE-2026-80889can: isotp: fix timer drain order, wakeup handling and tx_gen ordering

Description

In 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.

Timeline

Scores

No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.

EPSS (exploitation in 30 days)

0.18% · top 93% of all CVEs (13 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.

Affected products

• Linux · Linux

  • affected bbedeb67a9a684f2fb78c55bd3662c400526715e – < 8acab9fc66d6f426c36968c91a979f70784945a7
  • affected 377a8f500704da42ed86a4541ed930e9dcfdb2ea – < af7e25c649ed68cbad07f8185af0f31b892cbf29
  • affected 6da8119e8dd542194103139812d1a4b7dcd1aedd – < 2753722612d8824d3910096f93059f669009b0f0
  • affected 0b05eca9589f609e2491b528dccf683168a4cda8 – < bf5c4a8b24acb12739ebb9aea5510b007e4f5239
  • affected a7d90e7b5e75d7406c889fe36e9a61ee364a00cb – < deca7746b57d982cd4f0301f4443f56780c4a048
  • affected 37beb16e08cae94cc05840c7274225e3b0b38ae7 – < 10be509fa8fd95d1e47d40d1f68b0b26dfe9d572
  • affected 4f1fdf1a1c317bcac0c6b6c8e12642c9983de1ca – < 35c62ac98d06669aa3f0f38b7829eaca929a611e
  • affected cf070fe33bfbd1a4c21236078fadb35dd223a157 – < 050f010f920da17c1044a4f174766ad553e770b6

• Linux · Linux

  • affected 5.10.265 – < 5.10.267
  • affected 5.15.216 – < 5.15.218
  • affected 6.1.183 – < 6.1.185
  • affected 6.6.148 – < 6.6.151
  • affected 6.12.101 – < 6.12.103
  • affected 6.18.40 – < 6.18.44
  • affected 7.1.5 – < 7.1.8

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-71639 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

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Record last updated 4 Sept 2026, 17:11 UTC.