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CVE-2026-98681

Linux: smb: client: split cifsFileInfo bitfields to avoid shared-byte RMW races

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.17%Chance of exploitation activity in the next 30 days, higher than 5% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in3b8e7928cf1928555dc05d172dd02fb0e7692ec4Also 3786ee67658a2c80fef2544e7de2cd329e043cf9, 4165641d06ef44f3a31b77a28048b6c737e885e7 and 1 moreCVE List
Published18 Oct 2026Updated 21 Oct 2026CVE List

What fixes it

  • 3b8e7928cf1928555dc05d172dd02fb0e7692ec4LinuxCVE List
  • 3786ee67658a2c80fef2544e7de2cd329e043cf9LinuxCVE List
  • 4165641d06ef44f3a31b77a28048b6c737e885e7LinuxCVE List
  • 19465a9aeb664f1d710d0d22c07c31bfb7c85446LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 12

  • Linuxaffected: 3bc303c254335dbd7c7012cc1760b12f1d5514d3 before 3b8e7928cf1928555dc05d172dd02fb0e7692ec4CVE List
  • Linuxaffected: 3bc303c254335dbd7c7012cc1760b12f1d5514d3 before 3786ee67658a2c80fef2544e7de2cd329e043cf9CVE List
  • Linuxaffected: 3bc303c254335dbd7c7012cc1760b12f1d5514d3 before 4165641d06ef44f3a31b77a28048b6c737e885e7CVE List
  • Linuxaffected: 3bc303c254335dbd7c7012cc1760b12f1d5514d3 before d9d23d115610e0342e768f6cb525d91c7b154027CVE List
  • Linuxaffected: 3bc303c254335dbd7c7012cc1760b12f1d5514d3 before 19465a9aeb664f1d710d0d22c07c31bfb7c85446CVE List
  • Linuxaffected: 2.6.32CVE List
  • Linuxunaffected: all versions before 2.6.32CVE List
  • Linuxunaffected: 6.6.160 through 6.6.*CVE List
  • Linuxunaffected: 6.12.113 through 6.12.*CVE List
  • Linuxunaffected: 6.18.56 through 6.18.*CVE List
  • Linuxunaffected: 7.2.10 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 5