media: v4l2-compat-ioctl32: prevent go past max size

commit ea72fbf588ac9c017224dcdaa2019ff52ca56fee upstream. As warned by smatch: drivers/media/v4l2-core/v4l2-compat-ioctl32.c:879 put_v4l2_ext_controls32() warn: check for integer overflow 'count' The access_ok() logic should check for too big arrays too. Cc: [email protected] Signed-off-by: Mauro Carvalho Chehab <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
NobUser · Jul 3, 2018 · 1e6b50b · 1e6b50b
1 parent d6a267b
commit 1e6b50b
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -864,7 +864,7 @@ static int put_v4l2_ext_controls32(struct file *file,
 	    get_user(kcontrols, &kp->controls))
 		return -EFAULT;
 
-	if (!count)
+	if (!count || count > (U32_MAX/sizeof(*ucontrols)))
 		return 0;
 	if (get_user(p, &up->controls))
 		return -EFAULT;