CVEvulnerability
CVE-2026-31694
7.8 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-05-01
- Last modified
- 2026-10-23
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
fuse: reject oversized dirents in page cache
fuse_add_dirent_to_cache() computes a serialized dirent size from the
server-controlled namelen field and copies the dirent into a single
page-cache page. The existing logic only checks whether the dirent fits
in the remaining space of the current page and advances to a fresh page
if not. It never checks whether the dirent itself exceeds PAGE_SIZE.
As a result, a malicious FUSE server can return a dirent with
namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB
page systems this causes memcpy() to overflow the cache page by 24 bytes
into the following kernel page.
Reject dirents that cannot fit in a single page before copying them into
the readdir cache.
Affected configurations
• linux linux kernel (>= 6.15 < 6.18.25)
• linux linux kernel (>= 6.19 < 7.0.2)
• linux linux kernel 7.1
• siemens simatic s7-1500 tm mfp firmware
References
- https://git.kernel.org/stable/c/474ce83c96a55f2eeb14dee2be375eeadfdacdf5 Patch
- https://git.kernel.org/stable/c/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed Patch
- https://git.kernel.org/stable/c/7de93abfaae1b2dc94da8a07a36421bd073f1d8f Patch
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html Third Party Advisory