CVE-2026-98167

Summary

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

smb: client: fix server->total_read for compound encrypted PDUs

In receive_encrypted_standard(), server->total_read is left at the full decrypted frame size when walking sub-PDUs of a compound encrypted frame. As a result, cifs_handle_standard() passes this full size to smb2_check_message(), causing the PDU length guards to incorrectly validate the entire compound frame instead of the current sub-PDU.

This allows truncated non-last sub-PDUs to bypass length validation, leading to out-of-bounds reads in smb2_get_data_area_len().

Fix this by setting server->total_read to the true length of the current sub-PDU: next_cmd for non-last sub-PDUs, and the remaining pdu_length for the last one.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 8703539d22fdbc13dd2db090ee199c3a427b8ea0affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < e78fc1d240b27349b45a0f1c3e3c2c401d7e230daffected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < a46eb242e9eef3a3897d166748b23303c516e870affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < ebb8a075fdc7af3d196a4f158a0e18dbc394c0e3affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 282b72f9a7ef31296c48366db4128882999cc048affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < f73726b83e4756fdaa099e1bc1143293bd57ad79affected
LinuxLinux4.19affected
LinuxLinux0 < 4.19unaffected
LinuxLinux6.1.189 <= 6.1.*unaffected
LinuxLinux6.6.158 <= 6.6.*unaffected
LinuxLinux6.12.112 <= 6.12.*unaffected
LinuxLinux6.18.54 <= 6.18.*unaffected
LinuxLinux7.2.8 <= 7.2.*unaffected
LinuxLinux7.3-rc4 <= *unaffected

Weaknesses

References