CVEvulnerability
CVE-2026-98126
5.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-09-25
- Last modified
- 2026-10-22
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-770
Description
In the Linux kernel, the following vulnerability has been resolved:
smb/client: validate new EOF for zero range
When FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE,
smb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing
the file to grow beyond the caller's file-size limit.
Fix this by calling inode_newsize_ok() before sending the zero-range
request when the operation would extend EOF.
Reproducer, using a file on a CIFS mount:
bash -c '
FILE=/mnt/cifs/repro
trap "" SIGXFSZ
ulimit -f 3072
truncate -s 2M "$FILE"
fallocate --zero-range -o 0 -l 4M "$FILE"
echo "fallocate rc=$?"
stat -c "file size=%s" "$FILE"
'
Before this change, the operation succeeds despite the 3 MiB limit:
fallocate rc=0
file size=4194304
After this change, fallocate fails and leaves the file at 2 MiB.
Affected configurations
• linux linux kernel (>= 5.1 < 6.6.160)
• linux linux kernel (>= 6.7 < 6.12.111)
• linux linux kernel (>= 6.13 < 6.18.53)
• linux linux kernel (>= 6.19 < 7.2.7)
• linux linux kernel 7.3
Related
Weakness · CWE (1)
- CWE-770 Allocation of Resources Without Limits or Throttling weakness
References
- https://git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828 Patch
- https://git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a Patch
- https://git.kernel.org/stable/c/5fbd8848f2e25c8163896ec52863df2305a3bb63 Patch
- https://git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4 Patch
- https://git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6 Patch