[PATCH] fddi/skfp: fix null pointer dereference in smt.c

[Siddarth G]

In smt_string_swap(), when a closing bracket ']' is encountered
before any opening bracket '[' open_paren would be NULL,
and assigning it to format would lead to a null pointer being
dereferenced in the format++ statement.

Add a check to verify open_paren is non-NULL before assigning
it to format

Fixes: CID 100271 (Coverity Scan)

Signed-off-by: Siddarth G <siddarthsgml@xxxxxxxxx>
---
 drivers/net/fddi/skfp/smt.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/fddi/skfp/smt.c b/drivers/net/fddi/skfp/smt.c
index dd15af4e98c2..174f279b89ac 100644
--- a/drivers/net/fddi/skfp/smt.c
+++ b/drivers/net/fddi/skfp/smt.c
@@ -1857,7 +1857,8 @@ static void smt_string_swap(char *data, const char *format, int len)
 			open_paren = format ;
 			break ;
 		case ']' :
-			format = open_paren ;
+			if (open_paren)
+				format = open_paren ;
 			break ;
 		case '1' :
 		case '2' :
-- 
2.43.0