smb/client: validate new EOF for zero range
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-770.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.1 and later | 6.6.160, 6.12.111, 6.18.53, 7.2.7, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 5.1 and later Fixed in 6.6.160, 6.12.111, 6.18.53, 7.2.7, 7.3 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.111, 6.18.53, 7.2.7, 7.3
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-98126
- 2026-10-03 Alias added: GHSA-788x-356f-432m
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/Linux@5fbd8848f2e25c8163896ec52863df2305a3bb63, Linux/[email protected] · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-23 CVSS score added · NVD
- 2026-10-23 Weakness changed · NVD
- 2026-11-07 Affected versions changed · Red Hat
References
Patch 5
- https://git.kernel.org/stable/c/5fbd8848f2e25c8163896ec52863df2305a3bb63
- https://git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a
- https://git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828
- https://git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6
- https://git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-98126 · CVE Program
- CVE-2026-98126 · NVD
- FIRST EPSS
- GHSA-788x-356f-432m · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98126 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences