From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89740: serial: imx: serialize imx_uart_ports[] lifetime
Date: Fri, 11 Sep 2026 21:47:09 +0200 [thread overview]
Message-ID: <2026091104-CVE-2026-89740-ee43@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
serial: imx: serialize imx_uart_ports[] lifetime
imx_uart_probe() publishes its devm-allocated port in imx_uart_ports[]
before uart_add_one_port() because console setup uses the table. The entry
is not cleared when adding the port fails or after removal, leaving a
dangling pointer.
A sibling probe can register the shared console through that stale entry.
This was reproduced under KASAN on QEMU mcimx6ul-evk by unbinding a
sibling UART, unbinding the console UART and rebinding the sibling.
Keep the entry valid through uart_remove_one_port(), then clear it. Protect
port addition and removal together with their table updates so sibling
operations cannot interleave. Reject an occupied slot rather than
clobbering an active port during a duplicate-line probe.
The Linux kernel CVE team has assigned CVE-2026-89740 to this issue.
Affected and fixed versions
===========================
Issue introduced in 2.6.27 with commit dbff4e9ea2e83fda89143389bfb229cb29425a32 and fixed in 6.12.109 with commit 681696ae9e4a28bdf54893c807dfe4a6c08e30a5
Issue introduced in 2.6.27 with commit dbff4e9ea2e83fda89143389bfb229cb29425a32 and fixed in 6.18.50 with commit 28b932202fcdbeb2ef58d89ce4363f480433c234
Issue introduced in 2.6.27 with commit dbff4e9ea2e83fda89143389bfb229cb29425a32 and fixed in 7.2.4 with commit 7429dce56a73bc080a8c072edb167106f73a08ae
Issue introduced in 2.6.27 with commit dbff4e9ea2e83fda89143389bfb229cb29425a32 and fixed in 7.3-rc1 with commit 8b0b29fdcb47907ae0296b8fe829e918e05e300f
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-2026-89740
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/imx.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/681696ae9e4a28bdf54893c807dfe4a6c08e30a5
https://git.kernel.org/stable/c/28b932202fcdbeb2ef58d89ce4363f480433c234
https://git.kernel.org/stable/c/7429dce56a73bc080a8c072edb167106f73a08ae
https://git.kernel.org/stable/c/8b0b29fdcb47907ae0296b8fe829e918e05e300f
reply other threads:[~2026-09-11 20:06 UTC|newest]
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