From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-43365: xfs: fix undersized l_iclog_roundoff values
Date: Fri, 8 May 2026 16:21:34 +0200 [thread overview]
Message-ID: <2026050827-CVE-2026-43365-b7ce@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix undersized l_iclog_roundoff values
If the superblock doesn't list a log stripe unit, we set the incore log
roundoff value to 512. This leads to corrupt logs and unmountable
filesystems in generic/617 on a disk with 4k physical sectors...
XFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c
XFS (sda1): Torn write (CRC failure) detected at log block 0x318e. Truncating head block from 0x3197.
XFS (sda1): failed to locate log tail
XFS (sda1): log mount/recovery failed: error -74
XFS (sda1): log mount failed
XFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c
XFS (sda1): Ending clean mount
...on the current xfsprogs for-next which has a broken mkfs. xfs_info
shows this...
meta-data=/dev/sda1 isize=512 agcount=4, agsize=644992 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=1 metadir=1
data = bsize=4096 blocks=2579968, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=1
log =internal log bsize=4096 blocks=16384, version=2
= sectsz=4096 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
= rgcount=0 rgsize=268435456 extents
= zoned=0 start=0 reserved=0
...observe that the log section has sectsz=4096 sunit=0, which means
that the roundoff factor is 512, not 4096 as you'd expect. We should
fix mkfs not to generate broken filesystems, but anyone can fuzz the
ondisk superblock so we should be more cautious. I think the inadequate
logic predates commit a6a65fef5ef8d0, but that's clearly going to
require a different backport.
The Linux kernel CVE team has assigned CVE-2026-43365 to this issue.
Affected and fixed versions
===========================
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 5.15.203 with commit 5afae524f83d6a18517298491a5624cb0eae5029
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 6.1.167 with commit 2ecda4b83749c1fef0c9dea4fd5e8b513aba3e40
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 6.6.130 with commit 41e91dff2d3974730b5ee50daa8e27ec254cbf91
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 6.12.78 with commit e88ce9f0536f3b2149afb70625cfc4bd74a4ac6d
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 6.18.19 with commit 446a1f5bb64ba38adb93cb043ff0f7b85e8937ca
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 6.19.9 with commit 5e7148402dfc4a5b7894d8e97b15e5c2e70924aa
Issue introduced in 5.14 with commit a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 and fixed in 7.0 with commit 52a8a1ba883defbfe3200baa22cf4cd21985d51a
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-2026-43365
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:
fs/xfs/xfs_log.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/5afae524f83d6a18517298491a5624cb0eae5029
https://git.kernel.org/stable/c/2ecda4b83749c1fef0c9dea4fd5e8b513aba3e40
https://git.kernel.org/stable/c/41e91dff2d3974730b5ee50daa8e27ec254cbf91
https://git.kernel.org/stable/c/e88ce9f0536f3b2149afb70625cfc4bd74a4ac6d
https://git.kernel.org/stable/c/446a1f5bb64ba38adb93cb043ff0f7b85e8937ca
https://git.kernel.org/stable/c/5e7148402dfc4a5b7894d8e97b15e5c2e70924aa
https://git.kernel.org/stable/c/52a8a1ba883defbfe3200baa22cf4cd21985d51a
reply other threads:[~2026-05-08 14:22 UTC|newest]
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