Subject: CVE-2023-52757: smb: client: fix potential deadlock when releasing mids

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

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

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

smb: client: fix potential deadlock when releasing mids

All release_mid() callers seem to hold a reference of @mid so there is
no need to call kref_put(&mid->refcount, __release_mid) under
@server->mid_lock spinlock.  If they don't, then an use-after-free bug
would have occurred anyways.

By getting rid of such spinlock also fixes a potential deadlock as
shown below

CPU 0                                CPU 1
------------------------------------------------------------------
cifs_demultiplex_thread()            cifs_debug_data_proc_show()
 release_mid()
  spin_lock(&server->mid_lock);
                                     spin_lock(&cifs_tcp_ses_lock)
				      spin_lock(&server->mid_lock)
  __release_mid()
   smb2_find_smb_tcon()
    spin_lock(&cifs_tcp_ses_lock) *deadlock*

The Linux kernel CVE team has assigned CVE-2023-52757 to this issue.

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

	Fixed in 6.1.64 with commit 9eb44db68c5b
	Fixed in 6.5.13 with commit b9bb9607b1fc
	Fixed in 6.6.3 with commit c1a5962f1462
	Fixed in 6.7 with commit e6322fd177c6

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-2023-52757
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/cifsproto.h
	fs/smb/client/smb2misc.c
	fs/smb/client/transport.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/9eb44db68c5b7f5aa22b8fc7de74a3e2e08d1f29
	https://git.kernel.org/stable/c/b9bb9607b1fc12fca51f5632da25b36975f599bf
	https://git.kernel.org/stable/c/c1a5962f1462b64fe7b69f20a4b6af8067bc2d26
	https://git.kernel.org/stable/c/e6322fd177c6885a21dd4609dc5e5c973d1a2eb7