Received-SPF: pass (google.com: domain of linux-kernel+bounces-48100-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Date: Thu, 1 Feb 2024 15:18:52 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Shyam Prasad N <sprasad@microsoft.com>
Cc: Steve French <sfrench@samba.org>, Paulo Alcantara <pc@manguebit.com>,
	Ronnie Sahlberg <ronniesahlberg@gmail.com>,
	Tom Talpey <tom@talpey.com>, linux-cifs@vger.kernel.org,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH] smb: client: Fix a double lock bug in smb2_reconnect()
Message-ID: <bf90de00-4d6a-4440-b6a1-42ac9e358158@moroto.mountain>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

This goto will try to lock spin_lock(&ses->ses_lock) twice which will
lead to a deadlock.

Fixes: 17525952fa83 ("cifs: make sure that channel scaling is done only once")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 fs/smb/client/smb2pdu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 2837fc4465a7..dcd3f6f08c7f 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -401,7 +401,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 
 	spin_lock(&ses->ses_lock);
 	if (ses->flags & CIFS_SES_FLAG_SCALE_CHANNELS)
-		goto skip_add_channels;
+		goto skip_add_channels_locked;
 	ses->flags |= CIFS_SES_FLAG_SCALE_CHANNELS;
 	spin_unlock(&ses->ses_lock);
 
@@ -448,6 +448,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 
 skip_add_channels:
 	spin_lock(&ses->ses_lock);
+skip_add_channels_locked:
 	ses->flags &= ~CIFS_SES_FLAG_SCALE_CHANNELS;
 	spin_unlock(&ses->ses_lock);
 
-- 
2.43.0