[PATCH] SMB3: Fix resource leak if an unexpected dialect is returned

[Christophe JAILLET]

If we receive an unexpected dialect, we must free some resources before
returning.

Branch to the existing error hangling path to fix it.

Fixes: 9764c02fcbad ("SMB3: Add support for multidialect negotiate (SMB2.1 and 
later)")
Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
---
 fs/cifs/smb2pdu.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 6f0e6343c15e..29025398d7d2 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -554,18 +554,21 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses 
*ses)
                if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
                        cifs_dbg(VFS,
                                "SMB2 dialect returned but not requested\n");
-                       return -EIO;
+                       rc = -EIO;
+                       goto neg_exit;
                } else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
                        cifs_dbg(VFS,
                                "SMB2.1 dialect returned but not requested\n");
-                       return -EIO;
+                       rc = -EIO;
+                       goto neg_exit;
                }
        } else if (strcmp(ses->server->vals->version_string,
                   SMBDEFAULT_VERSION_STRING) == 0) {
                if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
                        cifs_dbg(VFS,
                                "SMB2 dialect returned but not requested\n");
-                       return -EIO;
+                       rc = -EIO;
+                       goto neg_exit;
                } else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
                        /* ops set to 3.0 by default for default so update */
                        ses->server->ops = &smb21_operations;
@@ -575,7 +578,8 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
                /* if requested single dialect ensure returned dialect matched 
*/
                cifs_dbg(VFS, "Illegal 0x%x dialect returned: not requested\n",
                        le16_to_cpu(rsp->DialectRevision));
-               return -EIO;
+               rc = -EIO;
+               goto neg_exit;
        }
 
        cifs_dbg(FYI, "mode 0x%x\n", rsp->SecurityMode);
-- 
2.11.0