CVE-2026-98452: smb: client: clean up failed cached directory opens

CVE-2026-98452: smb: client: clean up failed cached directory opens

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

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.

The Linux kernel CVE team has assigned CVE-2026-98452 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.1 with commit b0f6df737a1c5d9d5ff90cc946205d8af46cc067 and fixed in 6.12.112 with commit 48958ddda3d7eee3600261e2d90671f63e055dc4
	Issue introduced in 5.1 with commit b0f6df737a1c5d9d5ff90cc946205d8af46cc067 and fixed in 6.18.55 with commit abab661eed00fa102d3c35ddf1cce4f687e718c1
	Issue introduced in 5.1 with commit b0f6df737a1c5d9d5ff90cc946205d8af46cc067 and fixed in 7.2.9 with commit 7c1509598a4fdfb54cb09ce33e4405bd6dbd8295
	Issue introduced in 5.1 with commit b0f6df737a1c5d9d5ff90cc946205d8af46cc067 and fixed in 7.3-rc5 with commit d2ff5fb93ea83034025850266b5eed391f96b825

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-98452
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/smb/client/cached_dir.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/48958ddda3d7eee3600261e2d90671f63e055dc4
	https://git.kernel.org/stable/c/abab661eed00fa102d3c35ddf1cce4f687e718c1
	https://git.kernel.org/stable/c/7c1509598a4fdfb54cb09ce33e4405bd6dbd8295
	https://git.kernel.org/stable/c/d2ff5fb93ea83034025850266b5eed391f96b825