CVE 8.2 HIGH

xfs: fix undersized l_iclog_roundoff values_CVE-2026-43365

8.2 / 10
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

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.

Basic Information

ID CVE-2026-43365
Source Linux
Published May 8, 2026 at 14:21
Modified May 11, 2026 at 06:33

Affected Product

Vendor Linux
Product Linux
Version a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Affected Versions Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48
Linux Linux 5.14

References

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