CVE-2026-98126
Linux kernel: denial of service
- Risk score
- 43/100
- CVSS
- 5.5 v3.1
- Exploit chance (30 days)
- 0.1%
- Published
- 25 Sep 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 calli…
- Affected
- Linux kernel
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 5.5 medium
- On your watchlist: linux kernel
References
- https://git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828
- https://git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a
- https://git.kernel.org/stable/c/5fbd8848f2e25c8163896ec52863df2305a3bb63
- https://git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4
- https://git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6
Original 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.
Last activity 25 Sep 2026. Patch Forecast updates every hour.