What’s Vulnerable › Vulnerabilities

CVE-2026-98681: smb: client: split cifsFileInfo bitfields to avoid shared-byte RMW races

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-18 · updated 2026-10-30

Description

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.

Affected products

• Linux: 2.6.32 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/19465a9aeb664f1d710d0d22c07c31bfb7c85446
• https://git.kernel.org/stable/c/3786ee67658a2c80fef2544e7de2cd329e043cf9
• https://git.kernel.org/stable/c/3b8e7928cf1928555dc05d172dd02fb0e7692ec4
• https://git.kernel.org/stable/c/4165641d06ef44f3a31b77a28048b6c737e885e7
• https://git.kernel.org/stable/c/7fa619367869be705942f087b2ecd209efc78fe1
• https://git.kernel.org/stable/c/d9d23d115610e0342e768f6cb525d91c7b154027
• https://git.kernel.org/stable/c/e961baf9c1a4f2e93a55f8eb2c6151fc27b96a4c
• https://git.kernel.org/stable/c/f255e87b4f7eda568c37d6eae5db1d1a8aca5968

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