[PATCH v2] cifs: smb2pdu: Fix potential NULL pointer dereference
From: Gustavo A. R. Silva
Date: Tue Apr 03 2018 - 17:00:48 EST
tcon->ses is being dereferenced before it is null checked, hence
there is a potential null pointer dereference.
Fix this by moving the pointer dereference after tcon->ses has
been properly null checked.
Addresses-Coverity-ID: 1467426 ("Dereference before null check")
Fixes: 93012bf98416 ("cifs: add server->vals->header_preamble_size")
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
Changes in v2:
- Update subject.
fs/cifs/smb2pdu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index f7741ce..e5ac474 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3454,7 +3454,7 @@ static int
build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level,
int outbuf_len, u64 persistent_fid, u64 volatile_fid)
{
- struct TCP_Server_Info *server = tcon->ses->server;
+ struct TCP_Server_Info *server;
int rc;
struct smb2_query_info_req *req;
unsigned int total_len;
@@ -3464,6 +3464,8 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level,
if ((tcon->ses == NULL) || (tcon->ses->server == NULL))
return -EIO;
+ server = tcon->ses->server;
+
rc = smb2_plain_req_init(SMB2_QUERY_INFO, tcon, (void **) &req,
&total_len);
if (rc)
--
2.7.4