[PATCH 5.8 25/85] vboxsf: Fix the check for the old binary mount-arguments struct

[Greg Kroah-Hartman]

From: Hans de Goede <hdegoede@xxxxxxxxxx>

[ Upstream commit 9d682ea6bcc76b8b2691c79add59f7d99c881635 ]

Fix the check for the mainline vboxsf code being used with the old
mount.vboxsf mount binary from the out-of-tree vboxsf version doing
a comparison between signed and unsigned data types.

This fixes the following smatch warnings:

fs/vboxsf/super.c:390 vboxsf_parse_monolithic() warn: impossible condition '(options[1] == (255)) => ((-128)-127 == 255)'
fs/vboxsf/super.c:391 vboxsf_parse_monolithic() warn: impossible condition '(options[2] == (254)) => ((-128)-127 == 254)'
fs/vboxsf/super.c:392 vboxsf_parse_monolithic() warn: impossible condition '(options[3] == (253)) => ((-128)-127 == 253)'

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/vboxsf/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/vboxsf/super.c b/fs/vboxsf/super.c
index 8fe03b4a0d2b0..25aade3441922 100644
--- a/fs/vboxsf/super.c
+++ b/fs/vboxsf/super.c
@@ -384,7 +384,7 @@ fail_nomem:
 
 static int vboxsf_parse_monolithic(struct fs_context *fc, void *data)
 {
-	char *options = data;
+	unsigned char *options = data;
 
 	if (options && options[0] == VBSF_MOUNT_SIGNATURE_BYTE_0 &&
 		       options[1] == VBSF_MOUNT_SIGNATURE_BYTE_1 &&
-- 
2.25.1