CVE-2026-89575: dm raid1: reserve space for NUL-terminator in build_constructor_string()

CVE-2026-89575: dm raid1: reserve space for NUL-terminator in build_constructor_string()

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

dm raid1: reserve space for NUL-terminator in build_constructor_string()

Reserve space for the termination NUL after the maximum 20 decimal
digits of a long long value to avoid buffer overflow in sprintf().

The Linux kernel CVE team has assigned CVE-2026-89575 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 2.6.31 with commit f5db4af466e2dca0fe822019812d586ca910b00c and fixed in 6.12.109 with commit 0a3657ebd6b517b60cdc5123894047616974e25b
	Issue introduced in 2.6.31 with commit f5db4af466e2dca0fe822019812d586ca910b00c and fixed in 6.18.50 with commit 644140527ae494cedf3b5c0ecd16287deaea7a66
	Issue introduced in 2.6.31 with commit f5db4af466e2dca0fe822019812d586ca910b00c and fixed in 7.2.4 with commit f79b53ca3a68a46c6fc3b30b148d1dfb1b33ea8b
	Issue introduced in 2.6.31 with commit f5db4af466e2dca0fe822019812d586ca910b00c and fixed in 7.3-rc1 with commit 73c37fe54cd056d07461b142ab0b8b81e1ef6ad8

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-2026-89575
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/md/dm-log-userspace-base.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/0a3657ebd6b517b60cdc5123894047616974e25b
	https://git.kernel.org/stable/c/644140527ae494cedf3b5c0ecd16287deaea7a66
	https://git.kernel.org/stable/c/f79b53ca3a68a46c6fc3b30b148d1dfb1b33ea8b
	https://git.kernel.org/stable/c/73c37fe54cd056d07461b142ab0b8b81e1ef6ad8