From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4A3303F165C for ; Fri, 8 May 2026 14:27:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778250448; cv=none; b=MG2keFB1vQoLzyNFG8gHnPm7kBqm/L7mxadFYlTctHJqBNkMrpEc7NMygDzTpOiLay3xQD14U4E06LSGguML2pAihnIZJyrBtefz/xbqTiBc1VG69U+VtQ0usjNNhFOWkHNMbCv+kN8l2dGjFmucogDC3H+MR3DYoxyNdeAuOrA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778250448; c=relaxed/simple; bh=6Ax2kMWhBgJeHAsttYYQeqzD3qmiuVdefnwWKZL3dsQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=egu+WOarDPFwNCP5Se5mS+pZIsiU26IMV/3qxOWyGG0TSxeC9XRAeQNoMVLAHiJxpaydObQBa4eku0tCwU2yYNqDzCiXt0hVa2JJkigL1iWlbj3SrnUKL8+HdAru/mQ4i+p5L9ge2jQsrHv9aBEz/w/Nted1LLjVa2Z8Qohwohg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=X4kaZ+JU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="X4kaZ+JU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4636C2BCB0; Fri, 8 May 2026 14:27:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778250448; bh=6Ax2kMWhBgJeHAsttYYQeqzD3qmiuVdefnwWKZL3dsQ=; h=From:To:Cc:Subject:Date:Reply-To:From; b=X4kaZ+JUv/d+j6z5aV+fkccJTc1UJ6EuTSsEXPIOu2ddWOJueICVv/RCHy/mEkBaO 6EsKa0Jvo/TYUOnRqmZ5enfPSm2tML7x37gd3qpVmqzx7kRTM5pvJRYiisgV7496Sj iXRKF3c+xouFkT06a/yGDjsUYfuC+4jMdhp63YTg= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-43458: serial: caif: hold tty->link reference in ldisc_open and ser_release Date: Fri, 8 May 2026 16:23:07 +0200 Message-ID: <2026050800-CVE-2026-43458-d72f@gregkh> X-Mailer: git-send-email 2.54.0 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=3617; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=gN2HOD95E+3HgQ6NEZ+3QMPeMsncD4PRUjB+PR0w3hk=; b=owGbwMvMwCRo6H6F97bub03G02pJDJl/P3ZUHtv9zS489o+Fp8L781Nrjh2V228Y1bFs+u7Mj ZOn/sz63hHLwiDIxCArpsjyZRvP0f0VhxS9DG1Pw8xhZQIZwsDFKQATWaHGML9e9MJCmcZFrSoe HIeaFTwYnnwNNGSYK5P2MepC95THsUVcq5wFeboXvzosBwA= 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: serial: caif: hold tty->link reference in ldisc_open and ser_release A reproducer triggers a KASAN slab-use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access is on tty->link->port. Hold an extra kref on tty->link for the lifetime of the caif_serial line discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open() error path. With this change applied, the reproducer no longer triggers the UAF in my testing. The Linux kernel CVE team has assigned CVE-2026-43458 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 5.10.253 with commit 23a3ac2e2262a291498567418227b99e1f3606b1 Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 5.15.203 with commit 52135420e9f75853ea0c6cea7b736e3e98495f7d Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 6.1.167 with commit ca2ceba983bb23ea0202c2882d963253416654a3 Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 6.6.130 with commit 8460187b4852fd00bd1c76394358053f3fa4d089 Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 6.12.78 with commit 27e43356d0defb9fc7fa25265219a3ffeb7b3e98 Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 6.18.19 with commit 35b58d3bc716ebb9ebd10fe1cac8c1177242511c Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 6.19.9 with commit 97a0bb491cae39478c6225381f14e9ac67b7bba7 Issue introduced in 2.6.35 with commit e31d5a05948e4478ba8396063d1e1f39880928e2 and fixed in 7.0 with commit 288598d80a068a0e9281de35bcb4ce495f189e2a 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-2026-43458 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: drivers/net/caif/caif_serial.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/23a3ac2e2262a291498567418227b99e1f3606b1 https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3 https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089 https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98 https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7 https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a