SB2026102216 - Integer underflow in Linux kernel xfs libxfs

Description

This security bulletin contains information about 1 vulnerability.

1) Integer underflow (CVE-ID: CVE-2026-98446)

CWE-ID: CWE-191 - Integer underflow

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to disrupt filesystem free-space accounting, potentially causing a denial of service.

The vulnerability exists due to an integer underflow in the Linux kernel XFS function xfs_metafile_resv_init when the metadata reservation target falls below the space already used by the metadata btree file. A local user can trigger the affected reservation calculation to cause xfs_dec_fdblocks to subtract an excessively large amount of free space, potentially preventing filesystem space allocations.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/476582d754cdc5110f806001417fea6c77824c13
• https://git.kernel.org/stable/c/930a9c1c321efdaa3e7f8caecb0479cee3baf342
• https://git.kernel.org/stable/c/f0d8352a39f4a2e329ae45b71bb0d49e2ca0a6dc