[PATCH] staging: lustre: fix potential NULL pointer dereference

[PATCH] staging: lustre: fix potential NULL pointer dereference

[Michal Nazarewicz]

From: Michal Nazarewicz <mina86@mina86.com>

The rest of the code seem to imply that rmf_dumper may indeed be
NULL.  Change the code so that dumping is not even considered if
rmf_dumper callback is not set.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
---
 drivers/staging/lustre/lustre/ptlrpc/layout.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/lustre/lustre/ptlrpc/layout.c b/drivers/staging/lustre/lustre/ptlrpc/layout.c
index 4d6ac686..f7b383c 100644
--- a/drivers/staging/lustre/lustre/ptlrpc/layout.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/layout.c
@@ -1829,8 +1829,11 @@ swabber_dumper_helper(struct req_capsule *pill,
 	else
 		do_swab = 0;
 
+	if (!field->rmf_dumper)
+		dump = 0;
+
 	if (!(field->rmf_flags & RMF_F_STRUCT_ARRAY)) {
-		if (dump && field->rmf_dumper) {
+		if (dump) {
 			CDEBUG(D_RPCTRACE, "Dump of %sfield %s follows\n",
 			       do_swab ? "unswabbed " : "", field->rmf_name);
 			field->rmf_dumper(value);
@@ -1856,7 +1859,7 @@ swabber_dumper_helper(struct req_capsule *pill,
 	for (p = value, i = 0, n = len / field->rmf_size;
 	     i < n;
 	     i++, p += field->rmf_size) {
-		if (dump && field->rmf_dumper) {
+		if (dump) {
 			CDEBUG(D_RPCTRACE, "Dump of %sarray field %s, "
 			       "element %d follows\n",
 			       do_swab ? "unswabbed " : "", field->rmf_name, i);
@@ -1865,7 +1868,7 @@ swabber_dumper_helper(struct req_capsule *pill,
 		if (!do_swab)
 			continue;
 		swabber(p);
-		if (dump && field->rmf_dumper) {
+		if (dump) {
 			CDEBUG(D_RPCTRACE, "Dump of swabbed array field %s, "
 			       "element %d follows\n", field->rmf_name, i);
 			field->rmf_dumper(value);
-- 
1.8.4.1