From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1766150AC0C for ; Fri, 4 Sep 2026 17:13:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788541991; cv=none; b=NQbbkc5NQozyjHH9EekJOUJ2v0LwOWeLZO8ev8hQS5wCJyNpIubeFaCmKZFRkDUsS+YfZTxYuRES+b2J06lvTqiPBFEme/pMvruacbBswD7eFsfUzFItu97cFy2PUPRWjeHaXsAvFGPOXiq2AM2SbKDe2gbV3u0P6MtJE36m2WY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788541991; c=relaxed/simple; bh=aKJAnuJ2R+6jKBGe8UG1q9rrCjsVDPa2R6oto6Enx9U=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=eruSxgAKB7Afek36VjOSkH5R3f7iXzhj/tVwoKu9mSnHBFm9Y0ReWtYgut2BIqUqtiX17/nYjdRrh92LK31K58xYSG6Y53gBTI8A3KL27Zyk+p9G6Zna+xtOpr4ulIS6pZB/06h+MW+Z74gXWSwbVmTqEF9dr+Vjwt/ploLniBs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gYEHlvvb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gYEHlvvb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C13AA1F00A3D; Fri, 4 Sep 2026 17:13:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788541989; bh=sL1QU7pdL103jqLfnquhpALJ65ypgn8cZy4EGCPYsA0=; h=From:To:Cc:Subject:Date:Reply-To; b=gYEHlvvbzn3cbRoqXdHbHb5C02XQ3Rwkj5rbs7aZ3ycPAyW9FrijsVE4/EE3GqdwI bemGouOVVeKAxWuiuhzPsFAZYD+0brb2K1kdeHsMuXxcV2XCQfcU7pLCJFqz8FayXN wtsP+9WOabPsDFrgEMW5RPW3ncGQRyVvYmPonWb8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80889: can: isotp: fix timer drain order, wakeup handling and tx_gen ordering Date: Fri, 4 Sep 2026 19:09:30 +0200 Message-ID: <2026090429-CVE-2026-80889-bf82@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4868; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=+lnDTmPkfYQmpvHr2rwdOzTOQHbYAc6W3FpW5eMFx6A=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmzfnv2Kytv8zhgkqJZts+usiw6tju9yyXuVIiH4Clby eWzai07YlkYBJkYZMUUWb5s4zm6v+KQopeh7WmYOaxMIEMYuDgFYCI9wQwLeng722KM33AkFxxJ lw5vqDgfdfknw4KrT0UC1+748HL2550Hv/hMnaA8SzkQAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman 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. The Linux kernel CVE team has assigned CVE-2026-80889 to this issue. Affected and fixed versions =========================== Issue introduced in 5.10.265 with commit bbedeb67a9a684f2fb78c55bd3662c400526715e and fixed in 5.10.267 with commit 8acab9fc66d6f426c36968c91a979f70784945a7 Issue introduced in 5.15.216 with commit 377a8f500704da42ed86a4541ed930e9dcfdb2ea and fixed in 5.15.218 with commit af7e25c649ed68cbad07f8185af0f31b892cbf29 Issue introduced in 6.1.183 with commit 6da8119e8dd542194103139812d1a4b7dcd1aedd and fixed in 6.1.185 with commit 2753722612d8824d3910096f93059f669009b0f0 Issue introduced in 6.6.148 with commit 0b05eca9589f609e2491b528dccf683168a4cda8 and fixed in 6.6.151 with commit bf5c4a8b24acb12739ebb9aea5510b007e4f5239 Issue introduced in 6.12.101 with commit a7d90e7b5e75d7406c889fe36e9a61ee364a00cb and fixed in 6.12.103 with commit deca7746b57d982cd4f0301f4443f56780c4a048 Issue introduced in 6.18.40 with commit 37beb16e08cae94cc05840c7274225e3b0b38ae7 and fixed in 6.18.44 with commit 10be509fa8fd95d1e47d40d1f68b0b26dfe9d572 Issue introduced in 7.1.5 with commit 4f1fdf1a1c317bcac0c6b6c8e12642c9983de1ca and fixed in 7.1.8 with commit 35c62ac98d06669aa3f0f38b7829eaca929a611e Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-80889 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/can/isotp.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/8acab9fc66d6f426c36968c91a979f70784945a7 https://git.kernel.org/stable/c/af7e25c649ed68cbad07f8185af0f31b892cbf29 https://git.kernel.org/stable/c/2753722612d8824d3910096f93059f669009b0f0 https://git.kernel.org/stable/c/bf5c4a8b24acb12739ebb9aea5510b007e4f5239 https://git.kernel.org/stable/c/deca7746b57d982cd4f0301f4443f56780c4a048 https://git.kernel.org/stable/c/10be509fa8fd95d1e47d40d1f68b0b26dfe9d572 https://git.kernel.org/stable/c/35c62ac98d06669aa3f0f38b7829eaca929a611e https://git.kernel.org/stable/c/050f010f920da17c1044a4f174766ad553e770b6