CVE Catalog

CVE-2026-80536

HighCVSS 8.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

4th percentile - higher than 4% of all known CVEs

Summary

In the Linux kernel XFS filesystem, during log recovery, the function xlog_recover_do_reg_buffer() copies data into a buffer based on a dirty bitmap without proper bounds checking. An attacker can supply a crafted filesystem image that causes an out-of-bounds write and corrupts the kernel heap. The issue is fixed by replacing the ASSERT with a real XFS_IS_CORRUPT() check that aborts recovery with -EFSCORRUPTED.

Risk Assessment

The vulnerability allows a local attacker with the ability to mount a crafted XFS image to cause kernel memory corruption, potentially leading to system crash or privilege escalation.

Recommendation

Apply a Linux kernel update containing the fix for this vulnerability. Restrict access to mounting untrusted XFS filesystem images.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: xfs: bounds-check buffer log item's dirty bitmap xlog_recover_do_reg_buffer() replays each dirty region described by a buffer log item's bitmap into the buffer read for that item: memcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT), item->ri_buf[i].iov_base, nbits << XFS_BLF_SHIFT); The destination offset (bit/nbits, from the logged dirty bitmap) and the buffer size (from the logged blf_len) are both attacker-controlled and otherwise unrelated, yet the only thing bounding the copy is an ASSERT(), which compiles away on production kernels. A crafted image logging a small blf_len together with a bitmap bit past the end of that buffer drives the memcpy() past the buffer's allocation, corrupting adjacent kernel heap during mount-time log recovery. This is reachable by anyone who can get a crafted image mounted -- the malicious-filesystem threat model XFS already guards against elsewhere. Turn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery of the buffer with -EFSCORRUPTED, consistent with the validate-and-fail idiom already used in xlog_recover_do_inode_buffer() and xfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes STATIC int and its three callers propagate the error. Found and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted image trips a slab-out-of-bounds write before this change and fails recovery cleanly with -EFSCORRUPTED after it.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS