Subject: CVE-2024-46742: smb/server: fix potential null-ptr-deref of lease_ctx_info in smb2_open()

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

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

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

smb/server: fix potential null-ptr-deref of lease_ctx_info in smb2_open()

null-ptr-deref will occur when (req_op_level == SMB2_OPLOCK_LEVEL_LEASE)
and parse_lease_state() return NULL.

Fix this by check if 'lease_ctx_info' is NULL.

Additionally, remove the redundant parentheses in
parse_durable_handle_context().

The Linux kernel CVE team has assigned CVE-2024-46742 to this issue.

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

	Fixed in 6.6.51 with commit 07f384c5be1f
	Fixed in 6.10.10 with commit 3b692794b81f
	Fixed in 6.11 with commit 4e8771a3666c

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-2024-46742
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/server/oplock.c
	fs/smb/server/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/07f384c5be1f8633b13f0a22616e227570450bc6
	https://git.kernel.org/stable/c/3b692794b81f2ecad69a4adbba687f3836824ada
	https://git.kernel.org/stable/c/4e8771a3666c8f216eefd6bd2fd50121c6c437db