CVE-2026-64391

Summary

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

ksmbd: use opener credentials for ADS I/O

Alternate data streams are stored as xattrs. Unlike regular file I/O, their read and write paths therefore call VFS xattr helpers which recheck inode permissions and LSM policy using the current task credentials.

Run ADS I/O with the credentials captured when the SMB handle was opened.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf44158485826c076335d6860d35872271a83791d < a8f5d39971bbad9340d49cd41b0e2da9452a649daffected
LinuxLinuxf44158485826c076335d6860d35872271a83791d < 2b4592cea214683de0f2ce6f8c22c097fb0ea1abaffected
LinuxLinuxf44158485826c076335d6860d35872271a83791d < 52a56cf53ec834c44ac1b4d16d585f26613ee5ceaffected
LinuxLinuxf44158485826c076335d6860d35872271a83791d < baa5e094886fffa7e6272edcb5e08be5ce28262caffected
LinuxLinux5.15affected
LinuxLinux0 < 5.15unaffected
LinuxLinux6.12.96 <= 6.12.*unaffected
LinuxLinux6.18.39 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References