linux-kernel - [PATCH 3.16 091/157] cifs: fix handle leak in smb2_query

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Message-ID: <lsq.1565469607.521653675@decadent.org.uk>
Date:   Sat, 10 Aug 2019 21:40:07 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, Denis Kirjanov <kda@...ux-powerpc.org>,
        "Steve French" <stfrench@...rosoft.com>,
        "Pavel Shilovsky" <pshilov@...rosoft.com>,
        "Ronnie Sahlberg" <lsahlber@...hat.com>
Subject: [PATCH 3.16 091/157] cifs: fix handle leak in smb2_query_symlink()

3.16.72-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ronnie Sahlberg <lsahlber@...hat.com>

commit e6d0fb7b34f264f72c33053558a360a6a734905e upstream.

If we enter smb2_query_symlink() for something that is not a symlink
and where the SMB2_open() would succeed we would never end up
closing this handle and would thus leak a handle on the server.

Fix this by immediately calling SMB2_close() on successfull open.

Signed-off-by: Ronnie Sahlberg <lsahlber@...hat.com>
Signed-off-by: Steve French <stfrench@...rosoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@...rosoft.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 fs/cifs/smb2ops.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -906,6 +906,8 @@ smb2_query_symlink(const unsigned int xi
 
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_buf);
 
+	if (!rc)
+		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 	if (!rc || !err_buf) {
 		kfree(utf16_path);
 		return -ENOENT;