CVE-2026-98447

A flaw was found in the Linux kernel's XFS file system. This vulnerability allows a local attacker to cause a Denial of Service (DoS) or potentially compromise the system through memory corruption. During the formatting of realtime reference count metadata, the kernel incorrectly calculates the buffer size and copies data beyond the allocated boundaries. An attacker could exploit this flaw by mounting or processing a specially crafted filesystem image.

An oversized memcpy in the XFS realtime refcount btree root conversion copies twice the valid key array size. This produces an out of bounds read and an out of bounds write that can corrupt memory located beyond the source and destination buffers. The issue can be reached while formatting or converting an ondisk realtime refcount btree root on an affected XFS filesystem. For the CVSS the PR:L reflects a local user or process that can perform filesystem operations capable of changing the affected realtime refcount metadata after the filesystem has already been configured and mounted. AC:H reflects the requirement for a specific XFS realtime configuration and a suitable btree root state. The issue is not directly network reachable. Impact is at least a local denial of service through kernel or filesystem failure and may include confidentiality and integrity impact because a concrete kernel memory corruption primitive is present.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.