linux-kernel - [PATCH V2] SMB2: Fix share type handling

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Date:   Fri, 12 May 2017 17:59:32 +0200
From:   Christophe JAILLET <christophe.jaillet@...adoo.fr>
To:     sfrench@...ba.org
Cc:     linux-cifs@...r.kernel.org, samba-technical@...ts.samba.org,
        linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>
Subject: [PATCH V2] SMB2: Fix share type handling

In fs/cifs/smb2pdu.h, we have:
#define SMB2_SHARE_TYPE_DISK    0x01
#define SMB2_SHARE_TYPE_PIPE    0x02
#define SMB2_SHARE_TYPE_PRINT   0x03

Knowing that, with the current code, the SMB2_SHARE_TYPE_PRINT case can
never trigger and printer share would be interpreted as disk share.

So, test the ShareType value for equality instead.

Fixes: faaf946a7d5b ("CIFS: Add tree connect/disconnect capability for SMB2")
Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
---
V2: use a 'switch' instead of some 'if'

The v1 and related comments are quite old. They can be found at:
   http://marc.info/?t=147976541800001&r=1&w=4
---
 fs/cifs/smb2pdu.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e0517f499c38..e4afdaae743f 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1240,15 +1240,19 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 		goto tcon_exit;
 	}
 
-	if (rsp->ShareType & SMB2_SHARE_TYPE_DISK)
+	switch (rsp->ShareType) {
+	case SMB2_SHARE_TYPE_DISK:
 		cifs_dbg(FYI, "connection to disk share\n");
-	else if (rsp->ShareType & SMB2_SHARE_TYPE_PIPE) {
+		break;
+	case SMB2_SHARE_TYPE_PIPE:
 		tcon->ipc = true;
 		cifs_dbg(FYI, "connection to pipe share\n");
-	} else if (rsp->ShareType & SMB2_SHARE_TYPE_PRINT) {
-		tcon->print = true;
+		break;
+	case SMB2_SHARE_TYPE_PRINT:
+		tcon->ipc = true;
 		cifs_dbg(FYI, "connection to printer\n");
-	} else {
+		break;
+	default:
 		cifs_dbg(VFS, "unknown share type %d\n", rsp->ShareType);
 		rc = -EOPNOTSUPP;
 		goto tcon_error_exit;
-- 
2.11.0