[PATCH 5.15 31/83] mm: fix dereferencing possible ERR_PTR

[Greg Kroah-Hartman]

From: Binyi Han <dantengknight@xxxxxxxxx>

commit 4eb5bbde3ccb710d3b85bfb13466612e56393369 upstream.

Smatch checker complains that 'secretmem_mnt' dereferencing possible
ERR_PTR().  Let the function return if 'secretmem_mnt' is ERR_PTR, to
avoid deferencing it.

Link: https://lkml.kernel.org/r/20220904074647.GA64291@cloud-MacBookPro
Fixes: 1507f51255c9f ("mm: introduce memfd_secret system call to create "secret" memory areas")
Signed-off-by: Binyi Han <dantengknight@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx>
Cc: Hagen Paul Pfeifer <hagen@xxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 mm/secretmem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -283,7 +283,7 @@ static int secretmem_init(void)
 
 	secretmem_mnt = kern_mount(&secretmem_fs);
 	if (IS_ERR(secretmem_mnt))
-		ret = PTR_ERR(secretmem_mnt);
+		return PTR_ERR(secretmem_mnt);
 
 	/* prevent secretmem mappings from ever getting PROT_EXEC */
 	secretmem_mnt->mnt_flags |= MNT_NOEXEC;