linux-kernel - [PATCH AUTOSEL 5.13 108/108] cifs: prevent NULL deref in cifs_compose_mount

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210714193800.52097-108-sashal@kernel.org>
Date:   Wed, 14 Jul 2021 15:38:00 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Paulo Alcantara <pc@....nz>, Steve French <stfrench@...rosoft.com>,
        Sasha Levin <sashal@...nel.org>, linux-cifs@...r.kernel.org,
        samba-technical@...ts.samba.org
Subject: [PATCH AUTOSEL 5.13 108/108] cifs: prevent NULL deref in cifs_compose_mount_options()

From: Paulo Alcantara <pc@....nz>

[ Upstream commit 03313d1c3a2f086bb60920607ab79ac8f8578306 ]

The optional @ref parameter might contain an NULL node_name, so
prevent dereferencing it in cifs_compose_mount_options().

Addresses-Coverity: 1476408 ("Explicit null dereferenced")
Signed-off-by: Paulo Alcantara (SUSE) <pc@....nz>
Signed-off-by: Steve French <stfrench@...rosoft.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/cifs/cifs_dfs_ref.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index c87c37cf2914..4e3c15cd403a 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -151,6 +151,9 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
 		return ERR_PTR(-EINVAL);
 
 	if (ref) {
+		if (WARN_ON_ONCE(!ref->node_name || ref->path_consumed < 0))
+			return ERR_PTR(-EINVAL);
+
 		if (strlen(fullpath) - ref->path_consumed) {
 			prepath = fullpath + ref->path_consumed;
 			/* skip initial delimiter */
-- 
2.30.2