Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
From:   Philipp Stanner <pstanner@redhat.com>
To:     Kees Cook <keescook@chromium.org>,
        Andy Shevchenko <andy@kernel.org>,
        Eric Biederman <ebiederm@xmission.com>,
        Christian Brauner <brauner@kernel.org>,
        David Disseldorp <ddiss@suse.de>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Siddh Raman Pant <code@siddh.me>,
        Nick Alcock <nick.alcock@oracle.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, Zack Rusin <zackr@vmware.com>
Cc:     VMware Graphics Reviewers <linux-graphics-maintainer@vmware.com>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        kexec@lists.infradead.org, linux-hardening@vger.kernel.org,
        Philipp Stanner <pstanner@redhat.com>,
        David Airlie <airlied@redhat.com>
Subject: [PATCH v3 3/5] kernel: watch_queue: copy user-array safely
Date:   Wed, 20 Sep 2023 14:36:11 +0200
Message-ID: <20230920123612.16914-5-pstanner@redhat.com>
In-Reply-To: <20230920123612.16914-2-pstanner@redhat.com>
References: <20230920123612.16914-2-pstanner@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Currently, there is no overflow-check with memdup_user().

Use the new function memdup_array_user() instead of memdup_user() for
duplicating the user-space array safely.

Suggested-by: David Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Zack Rusin <zackr@vmware.com>
---
 kernel/watch_queue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index d0b6b390ee42..778b4056700f 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -331,7 +331,7 @@ long watch_queue_set_filter(struct pipe_inode_info *pipe,
 	    filter.__reserved != 0)
 		return -EINVAL;
 
-	tf = memdup_user(_filter->filters, filter.nr_filters * sizeof(*tf));
+	tf = memdup_array_user(_filter->filters, filter.nr_filters, sizeof(*tf));
 	if (IS_ERR(tf))
 		return PTR_ERR(tf);
 
-- 
2.41.0