hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBSSQA CVE: NA ---------------------------------------- If an error occurs when port 139 is used to mount the CIFS, the mount process may racy with the reconnect process. If the mount process first sets tcpStatus to CifsExiting and then the reconnect process sets tcpStatus to CifsNeedReconnect later, the cifs_reconnect() function enters an infinite loop and and the cifsd process cannot exit. mount.cifs cifsd ------------------------------------------------------------------ cifs_do_mount cifs_smb3_do_mount cifs_mount mount_get_conns cifs_get_smb_ses cifs_demultiplex_thread cifs_negotiate_protocol smb2_need_neg smb2_negotiate SMB2_negotiate cifs_send_recv compound_send_recv wait_for_response cifs_read_from_socket cifs_readv_from_socket cifs_readv_from_socket smb2_can_echo cifs_reconnect do { generic_ip_connect cifs_sync_mid_result DeleteMidQEntry _cifs_mid_q_entry_release cifs_small_buf_release cifs_put_tcp_session tcpStatus = CifsExiting; // The status will not be changed later in mount.cifs. ip_rfc1001_connect smb_send __smb_send_rqst tcpStatus = CifsNeedReconnect; // infinite loop } while (tcpStatus == CifsNeedReconnect) This patch adds a check in __smb_send_rqst() to not change tcpStatus to CifsNeedReconnect if tcpStatus is CifsExiting. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> --- fs/cifs/transport.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index c6fd4223b3be..d634a7692e13 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -437,11 +437,14 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, /* * If we have only sent part of an SMB then the next SMB could * be taken as the remainder of this one. We need to kill the * socket so the server throws away the partial SMB */ - server->tcpStatus = CifsNeedReconnect; + spin_lock(&GlobalMid_Lock); + if (server->tcpStatus != CifsExiting) + server->tcpStatus = CifsNeedReconnect; + spin_unlock(&GlobalMid_Lock); trace_smb3_partial_send_reconnect(server->CurrentMid, server->hostname); } smbd_done: if (rc < 0 && rc != -EINTR) -- 2.34.3