[PATCH AUTOSEL 4.9 134/141] reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()

[Sasha Levin]

From: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>

[ Upstream commit aacee5446a2a1aa35d0a49dab289552578657fb4 ]

The variable inode may be NULL in reiserfs_insert_item(), but there is
no check before accessing the member of inode.

Fix this by adding NULL pointer check before calling reiserfs_debug().

Link: http://lkml.kernel.org/r/79c5135d-ff25-1cc9-4e99-9f572b88cc00@xxxxxxxxxx
Signed-off-by: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
Cc: zhengbin <zhengbin13@xxxxxxxxxx>
Cc: Hu Shiyuan <hushiyuan@xxxxxxxxxx>
Cc: Feilong Lin <linfeilong@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/reiserfs/stree.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c
index a97e352d05d3b..5f5fff0688776 100644
--- a/fs/reiserfs/stree.c
+++ b/fs/reiserfs/stree.c
@@ -2249,7 +2249,8 @@ int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
 	/* also releases the path */
 	unfix_nodes(&s_ins_balance);
 #ifdef REISERQUOTA_DEBUG
-	reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
+	if (inode)
+		reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
 		       "reiserquota insert_item(): freeing %u id=%u type=%c",
 		       quota_bytes, inode->i_uid, head2type(ih));
 #endif
-- 
2.20.1