CVE-2026-68457

Summary

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: use opener credentials for FSCTL mutations

SET_SPARSE, SET_ZERO_DATA and SET_COMPRESSION operate on an open SMB handle but call VFS xattr, fallocate or fileattr helpers with the current ksmbd worker credentials. Those helpers can revalidate inode permissions, ownership and LSM policy independently of the SMB handle access mask.

Run each operation with the credentials captured in the target file when the handle was opened. Keep credential handling local to these single-file FSCTLs rather than applying session credentials to the complete IOCTL handler, which also contains handle-less and multi-handle operations.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a8c18434e1f0d9f7989170bdb0490c0160baf065affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1e112c47ec5dd1942e2d4ca6e8e9b712238e20c2affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < fb1cae6302d58414ddf029e3f642711bd30243f7affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < e205f3e7e8c31a47cd11efb6cf663a527177e432affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cfb2c6f71d61ed807c9d7a7af331d406f1f31877affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c6394bcaf254c5baf9aff43376020be5db6d3316affected
LinuxLinux0 < 6.1.178affected
LinuxLinux0 < 6.6.145affected
LinuxLinux0 < 6.12.97affected
LinuxLinux0 < 6.18.40affected
LinuxLinux0 < 7.1.5affected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References