smb: client: clean up failed cached directory opens

Overview

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

smb: client: clean up failed cached directory opens

open_cached_dir() sends CREATE and QUERY_INFO as a compound request. If the CREATE succeeds but a later command returns an error, the function must retain the CREATE FID so common cleanup can issue SMB2_close(). It also must not treat a response error as a valid CREATE.

Validate the CREATE response before using its fields, record the FIDs, and mark the handle open before handling errors from later compound commands. Move the -EREMCHG reconnect handling before response validation so a missing response does not hide the reconnect request. Count the handle when it is marked open; confirmed close responses decrement the counter, while existing close retry behavior remains best effort on transport failures.

Affected

• Linux >= b0f6df737a1c5d9d5ff90cc946205d8af46cc067 < 48958ddda3d7eee3600261e2d90671f63e055dc4
• Linux >= b0f6df737a1c5d9d5ff90cc946205d8af46cc067 < abab661eed00fa102d3c35ddf1cce4f687e718c1
• Linux >= b0f6df737a1c5d9d5ff90cc946205d8af46cc067 < 7c1509598a4fdfb54cb09ce33e4405bd6dbd8295
• Linux >= b0f6df737a1c5d9d5ff90cc946205d8af46cc067 < d2ff5fb93ea83034025850266b5eed391f96b825
• Linux 5.1

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.