CVE-2026-64384: smb: client: fix change notify replay double-free

From: Greg Kroah-Hartman <[email protected]>

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

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

smb: client: fix change notify replay double-free

A response-bearing attempt can return a replayable error and free its
response buffer. If SMB2_notify_init() fails before the next send, cleanup
retains the previous buffer type and frees that response again.

Reset response bookkeeping before each attempt to prevent the stale free.

The Linux kernel CVE team has assigned CVE-2026-64384 to this issue.


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

	Issue introduced in 6.6.32 with commit 433042a91f9373241307725b52de573933ffedbf and fixed in 6.6.145 with commit 5821f9dbb8b5b24391850a13418e633edd0fb003
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 6.12.96 with commit d684f4134998085702009b94c35c2003fc9e72d3
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 6.18.39 with commit 52af1975f0dfae990c5a0e85872cc41be0e88a68
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 7.1.4 with commit 901891513951bc8322ece754863909ea45af95c6
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 7.2-rc1 with commit 145f820dcbb2cced374f2532f8a61a44dce4a615

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-2026-64384
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/smb2pdu.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/5821f9dbb8b5b24391850a13418e633edd0fb003
	https://git.kernel.org/stable/c/d684f4134998085702009b94c35c2003fc9e72d3
	https://git.kernel.org/stable/c/52af1975f0dfae990c5a0e85872cc41be0e88a68
	https://git.kernel.org/stable/c/901891513951bc8322ece754863909ea45af95c6
	https://git.kernel.org/stable/c/145f820dcbb2cced374f2532f8a61a44dce4a615