[PATCH 6.1 021/236] smb3: missing lock when picking channel

Greg Kroah-Hartman
2024-05-14T11:28:19Z

From: Steve French <stfrench@microsoft.com>

[ Upstream commit 8094a600245e9b28eb36a13036f202ad67c1f887 ]

Coverity spotted a place where we should have been holding the
channel lock when accessing the ses channel index.

Addresses-Coverity: 1582039 ("Data race condition (MISSING_LOCK)")
Cc: stable@vger.kernel.org
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/smb/client/transport.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c
index da2bef3b7ac27..3fdafb9297f13 100644
--- a/fs/smb/client/transport.c
+++ b/fs/smb/client/transport.c
@@ -1079,9 +1079,11 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
index = (uint)atomic_inc_return(&ses->chan_seq);
index %= ses->chan_count;
}
+
+ server = ses->chans[index].server;
spin_unlock(&ses->chan_lock);

- return ses->chans[index].server;
+ return server;
}

int
--
2.43.0