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 9CB181C695 for ; Sat, 14 Feb 2026 15:10:54 +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=1771081854; cv=none; b=o7AbQxL5moyzrpEEWBz3VtIFEM/3PFshVzyOHQf78WPyjmQ+Sqo//xl0ZLqGBilxEnhEzeKGQEugiKKufCDvKOStF48hQCxhuK6NCm5uQOBiBhgLK5t/Ffa+RtKvwyXGR7dTXm6ZWtVgweNQ1g3ofAhD0dkR4VQfXE3QcTYqtgo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771081854; c=relaxed/simple; bh=3c4cIjnJ8mmAmRCysBN5wv2jeb76T3hWInHjo8+i0ds=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=jyzoTgt6brfaT06x4DUjtmhQ+UvExT/YWJxP8ZRuvRlpyqtXY+pci7CDUhlEo9kO17IVpSglZGRlEiWx0UigHfTL/QteVJZMdG2lPN5jX7kL+q7/9ZPvF6xEPJ96fqsaY/2ZyRmUCj2vUFdBooR2nyQWetTSRsc1U6mqNCqCyF4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZSWGt6kM; 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="ZSWGt6kM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28BF4C16AAE; Sat, 14 Feb 2026 15:10:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771081854; bh=3c4cIjnJ8mmAmRCysBN5wv2jeb76T3hWInHjo8+i0ds=; h=From:To:Cc:Subject:Date:Reply-To:From; b=ZSWGt6kMqtKRjAZPCufBZ968q8TE8ZJ0eSOfAdq+YaKBo303oXPOH0osvdaySnnmN Vb3jaD8IbD2KMoebiU9dD5+3/lr3YjvUIctjCDWQ4wf4KV8BQ+2qjFrb4Hxvp6ZPnP 0YmMGneYNrOWFdNgSIOjjYstM4zgoDKFSkopNBKA= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-23115: serial: Fix not set tty->port race condition Date: Sat, 14 Feb 2026 16:10:07 +0100 Message-ID: <2026021406-CVE-2026-23115-64da@gregkh> X-Mailer: git-send-email 2.53.0 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=4458; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=t2K6nSR8y+ScaKglLWH43FZ08GwN+qRsKaeOIQdxlqw=; b=owGbwMvMwCRo6H6F97bub03G02pJDJkTJvhN/3aNu0ZszqO6K9aB7zevMlpVVFpt5fFW7v6WV 6pf6pL1O2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAiPTcZFpyJ03ro+8GnbMoE vVOHWM4fDJ1yUZ1hfvxGryrbaRv0A4v6/hh5vVh2aVf9VAA= 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: Fix not set tty->port race condition Revert commit bfc467db60b7 ("serial: remove redundant tty_port_link_device()") because the tty_port_link_device() is not redundant: the tty->port has to be confured before we call uart_configure_port(), otherwise user-space can open console without TTY linked to the driver. This tty_port_link_device() was added explicitly to avoid this exact issue in commit fb2b90014d78 ("tty: link tty and port before configuring it as console"), so offending commit basically reverted the fix saying it is redundant without addressing the actual race condition presented there. Reproducible always as tty->port warning on Qualcomm SoC with most of devices disabled, so with very fast boot, and one serial device being the console: printk: legacy console [ttyMSM0] enabled printk: legacy console [ttyMSM0] enabled printk: legacy bootconsole [qcom_geni0] disabled printk: legacy bootconsole [qcom_geni0] disabled ------------[ cut here ]------------ tty_init_dev: ttyMSM driver does not set tty->port. This would crash the kernel. Fix the driver! WARNING: drivers/tty/tty_io.c:1414 at tty_init_dev.part.0+0x228/0x25c, CPU#2: systemd/1 Modules linked in: socinfo tcsrcc_eliza gcc_eliza sm3_ce fuse ipv6 CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G S 6.19.0-rc4-next-20260108-00024-g2202f4d30aa8 #73 PREEMPT Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Qualcomm Technologies, Inc. Eliza (DT) ... tty_init_dev.part.0 (drivers/tty/tty_io.c:1414 (discriminator 11)) (P) tty_open (arch/arm64/include/asm/atomic_ll_sc.h:95 (discriminator 3) drivers/tty/tty_io.c:2073 (discriminator 3) drivers/tty/tty_io.c:2120 (discriminator 3)) chrdev_open (fs/char_dev.c:411) do_dentry_open (fs/open.c:962) vfs_open (fs/open.c:1094) do_open (fs/namei.c:4634) path_openat (fs/namei.c:4793) do_filp_open (fs/namei.c:4820) do_sys_openat2 (fs/open.c:1391 (discriminator 3)) ... Starting Network Name Resolution... Apparently the flow with this small Yocto-based ramdisk user-space is: driver (qcom_geni_serial.c): user-space: ============================ =========== qcom_geni_serial_probe() uart_add_one_port() serial_core_register_port() serial_core_add_one_port() uart_configure_port() register_console() | | open console | ... | tty_init_dev() | driver->ports[idx] is NULL | tty_port_register_device_attr_serdev() tty_port_link_device() <- set driver->ports[idx] The Linux kernel CVE team has assigned CVE-2026-23115 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit bfc467db60b76c30ca1f7f02088a219b6d5b6e8c and fixed in 6.18.8 with commit 2501c49306238b54a2de0f93de43d50ab6e76c84 Issue introduced in 6.15 with commit bfc467db60b76c30ca1f7f02088a219b6d5b6e8c and fixed in 6.19 with commit 32f37e57583f869140cff445feedeea8a5fea986 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-2026-23115 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/tty/serial/serial_core.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/2501c49306238b54a2de0f93de43d50ab6e76c84 https://git.kernel.org/stable/c/32f37e57583f869140cff445feedeea8a5fea986