Race condition in Linux kernel SMB client file info flags
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 2.6.32, in its SMB client, stores several cifsFileInfo flags in one shared bitfield byte. These flags are updated in code paths that can run at the same time under different locks, and bitfield assignments are read-modify-write operations, so one update can overwrite another. The flags were converted to separate bool fields to avoid these races.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: smb: client: split cifsFileInfo bitfields to avoid shared-byte RMW races The invalidHandle, swapfile, oplock_break_cancelled, offload, and status_file_deleted fields are stored in the same bitfield byte in struct cifsFileInfo, but are updated in different code paths that may run simultaneously, and are protected by different locks. Since bitfield assignments generate byte-level read-modify-write operations, a modification to one flag can overwrite a concurrent modification to another flag. To avoid these races, convert these flags from a bitfield to separate bool fields.
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 | 2.6.32 and later | 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.32 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3 Patch available CNA
Remediation
Upgrade to a fixed Linux kernel version: 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10 or 7.3. The sources list no fixed version for Red Hat Enterprise Linux 6, 7 and 8 or Red Hat OpenShift Container Platform 4.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98681
- 2026-10-18 Alias added: GHSA-f6j4-gqwr-mpr2
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/Linux@3b8e7928cf1928555dc05d172dd02fb0e7692ec4, Linux/[email protected] · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-23 CVSS score added · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Linux/[email protected], Linux/[email protected], Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
References
Other 8
- https://git.kernel.org/stable/c/f255e87b4f7eda568c37d6eae5db1d1a8aca5968
- https://git.kernel.org/stable/c/7fa619367869be705942f087b2ecd209efc78fe1
- https://git.kernel.org/stable/c/e961baf9c1a4f2e93a55f8eb2c6151fc27b96a4c
- https://git.kernel.org/stable/c/3b8e7928cf1928555dc05d172dd02fb0e7692ec4
- https://git.kernel.org/stable/c/3786ee67658a2c80fef2544e7de2cd329e043cf9
- https://git.kernel.org/stable/c/4165641d06ef44f3a31b77a28048b6c737e885e7
- https://git.kernel.org/stable/c/d9d23d115610e0342e768f6cb525d91c7b154027
- https://git.kernel.org/stable/c/19465a9aeb664f1d710d0d22c07c31bfb7c85446
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Sources
- CVE-2026-98681 · CVE Program
- CVE-2026-98681 · NVD
- FIRST EPSS
- GHSA-f6j4-gqwr-mpr2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98681 · 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