CVE-2026-89616fs/ntfs3: fix info-leak on partial LZNT decompress in ni_read_frame()

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix info-leak on partial LZNT decompress in ni_read_frame() ni_read_frame() decompresses an LZNT $DATA frame into the vmapped target pages and then trusts decompress_lznt()'s return value: unc_size = decompress_lznt(frame_ondisk, ondisk_size, frame_mem, frame_size); if ((ssize_t)unc_size < 0) err = unc_size; else if (!unc_size || unc_size > frame_size) err = -EINVAL; decompress_lznt() stops as soon as the compressed stream is exhausted (e.g. a zero chunk header) and returns the number of bytes it actually wrote, which may be far less than frame_size. The bytes between unc_size and frame_size are never written. The only memset() that follows zeroes the region beyond i_valid; when the frame lies entirely within the file's valid size that memset() does not run, so the gap retains whatever was in the just-vmapped pages. All pages are then marked uptodate and returned to userspace, disclosing uninitialized (recently-freed) kernel page memory. A crafted compressed file whose stream decompresses to only a few bytes leaks the remainder of every frame on a plain read(2), which is enough to recover kernel pointers and defeat KASLR. Zero the [unc_size, frame_size) tail immediately after a successful LZNT decompress so the remainder reads back as zero.

CVSS

7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Received

Record last updated

Sep 14, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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