CVE-2026-89781

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: fix out-of-bounds read in read_log_rec_buf()

read_log_rec_buf() copies a log record into a caller buffer starting at

u32 off = lsn_to_page_off(log, lsn) + log->record_header_len;

log->record_header_len (and log->data_off, used for the following pages)

comes verbatim from the on-disk restart area and is only checked for

8-byte alignment in is_rst_area_valid(), so off can exceed

log->page_size. "tail = log->page_size - off" then underflows and

memcpy() reads past the page_size-sized buffer returned by

read_log_page(), spilling adjacent slab memory into the replay buffer.

This is reachable by mounting a crafted NTFS image:

BUG: KASAN: slab-out-of-bounds in read_log_rec_buf+0x216/0x580

Read of size 64 at addr ffff88800a877ff8 by task exploit/127

read_log_rec_buf fs/ntfs3/fslog.c:2299

log_replay fs/ntfs3/fslog.c:4216

ntfs_loadlog_and_replay fs/ntfs3/fsntfs.c:324

ntfs_fill_super fs/ntfs3/super.c:13

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References