media: drivers/media/dvb-core: copy user arrays safely

[ Upstream commit 102fb77c2deb0df3683ef8ff7a6f4cf91dc456e2 ]

At several positions in dvb_frontend.c, memdup_user() is utilized to
copy userspace arrays. This is done without overflow checks.

Use the new wrapper memdup_array_user() to copy the arrays more safely.

Link: https://lore.kernel.org/linux-media/20231102191633.52592-2-pstanner@redhat.com
Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/media/dvb-core/dvb_frontend.c

@@ -2160,7 +2160,8 @@ static int dvb_frontend_handle_compat_ioctl(struct file *file, unsigned int cmd,
 		if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
 			return -EINVAL;
 
-		tvp = memdup_user(compat_ptr(tvps->props), tvps->num * sizeof(*tvp));
+		tvp = memdup_array_user(compat_ptr(tvps->props),
+					tvps->num, sizeof(*tvp));
 		if (IS_ERR(tvp))
 			return PTR_ERR(tvp);
 
@@ -2191,7 +2192,8 @@ static int dvb_frontend_handle_compat_ioctl(struct file *file, unsigned int cmd,
 		if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
 			return -EINVAL;
 
-		tvp = memdup_user(compat_ptr(tvps->props), tvps->num * sizeof(*tvp));
+		tvp = memdup_array_user(compat_ptr(tvps->props),
+					tvps->num, sizeof(*tvp));
 		if (IS_ERR(tvp))
 			return PTR_ERR(tvp);
 
@@ -2368,7 +2370,8 @@ static int dvb_get_property(struct dvb_frontend *fe, struct file *file,
 	if (!tvps->num || tvps->num > DTV_IOCTL_MAX_MSGS)
 		return -EINVAL;
 
-	tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp));
+	tvp = memdup_array_user((void __user *)tvps->props,
+				tvps->num, sizeof(*tvp));
 	if (IS_ERR(tvp))
 		return PTR_ERR(tvp);
 
@@ -2446,7 +2449,8 @@ static int dvb_frontend_handle_ioctl(struct file *file,
 		if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
 			return -EINVAL;
 
-		tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp));
+		tvp = memdup_array_user((void __user *)tvps->props,
+					tvps->num, sizeof(*tvp));
 		if (IS_ERR(tvp))
 			return PTR_ERR(tvp);