{"id":"CVE-2026-80889","summary":"can: isotp: fix timer drain order, wakeup handling and tx_gen ordering","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't\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't 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't 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's own generation.\n\n- isotp_tx_timeout(): on a claimed timeout, record the ECOMM error for\n  the timed-out transfer's 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't 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.","modified":"2026-09-06T03:46:55.848998604Z","published":"2026-09-04T17:11:05.854Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80889.json"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80889.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80889"},{"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":"bbedeb67a9a684f2fb78c55bd3662c400526715e"},{"fixed":"8acab9fc66d6f426c36968c91a979f70784945a7"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"377a8f500704da42ed86a4541ed930e9dcfdb2ea"},{"fixed":"af7e25c649ed68cbad07f8185af0f31b892cbf29"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6da8119e8dd542194103139812d1a4b7dcd1aedd"},{"fixed":"2753722612d8824d3910096f93059f669009b0f0"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0b05eca9589f609e2491b528dccf683168a4cda8"},{"fixed":"bf5c4a8b24acb12739ebb9aea5510b007e4f5239"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a7d90e7b5e75d7406c889fe36e9a61ee364a00cb"},{"fixed":"deca7746b57d982cd4f0301f4443f56780c4a048"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"37beb16e08cae94cc05840c7274225e3b0b38ae7"},{"fixed":"10be509fa8fd95d1e47d40d1f68b0b26dfe9d572"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4f1fdf1a1c317bcac0c6b6c8e12642c9983de1ca"},{"fixed":"35c62ac98d06669aa3f0f38b7829eaca929a611e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"cf070fe33bfbd1a4c21236078fadb35dd223a157"},{"fixed":"050f010f920da17c1044a4f174766ad553e770b6"}]}],"versions":["v5.10.266","v5.10.265","v5.15.217","v5.15.216","v6.1.184","v6.1.183","v6.6.150","v6.6.149","v6.6.148","v6.12.102","v6.12.101","v6.18.43","v6.18.42","v6.18.41","v6.18.40","v7.1.7","v7.1.6","v7.1.5"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80889.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.10.265"},{"fixed":"5.10.267"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.15.216"},{"fixed":"5.15.218"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.1.183"},{"fixed":"6.1.185"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.6.148"},{"fixed":"6.6.151"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.12.101"},{"fixed":"6.12.103"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.40"},{"fixed":"6.18.44"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.1.5"},{"fixed":"7.1.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80889.json"}}],"schema_version":"1.9.0"}