CVE-2026-64597: smb: client: fix double-free in SMB2_close() replay

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

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

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

smb: client: fix double-free in SMB2_close() replay

A response-bearing attempt can return a replayable error and free its
response buffer. If SMB2_close_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-2026-64597 to this issue.


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

	Issue introduced in 6.6.32 with commit 433042a91f9373241307725b52de573933ffedbf and fixed in 6.6.145 with commit 037511726228aaf165c7067ff2bfc88eaecdf1f3
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 6.12.96 with commit 0aa97edf7c347c0f54e7e60c4740574b8120c66a
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 6.18.39 with commit d15d83125007f673aec4323e1bbbaaffbe87ea13
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 7.1.4 with commit b18ed621dbfceecea5539848cddcb9272c9a61e1
	Issue introduced in 6.8 with commit 4f1fffa2376922f3d1d506e49c0fd445b023a28e and fixed in 7.2-rc1 with commit f96e1cdcb63ed3321142ff2fcdf784e32cda8fee

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-2026-64597
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/037511726228aaf165c7067ff2bfc88eaecdf1f3
	https://git.kernel.org/stable/c/0aa97edf7c347c0f54e7e60c4740574b8120c66a
	https://git.kernel.org/stable/c/d15d83125007f673aec4323e1bbbaaffbe87ea13
	https://git.kernel.org/stable/c/b18ed621dbfceecea5539848cddcb9272c9a61e1
	https://git.kernel.org/stable/c/f96e1cdcb63ed3321142ff2fcdf784e32cda8fee