From dc43ee1df9b95c4d9e17285926d64c4600340f1e Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 1 Jul 2021 12:22:47 -0500 Subject: [PATCH] cifs: make locking consistent around the server session status There were three places where we were not taking the spinlock around updates to server->tcpStatus when it was being modified. To be consistent (also removes Coverity warning) and to remove possibility of race best to lock all places where it is updated. Addresses-Coverity: 1399512 ("Data race condition") Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 3 ++- fs/cifs/connect.c | 4 ++++ fs/cifs/transport.c | 2 ++ 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 3100f8b66e60..921680fb7931 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -577,6 +577,7 @@ struct TCP_Server_Info { char server_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL]; struct smb_version_operations *ops; struct smb_version_values *vals; + /* updates to tcpStatus protected by GlobalMid_Lock */ enum statusEnum tcpStatus; /* what we think the status is */ char *hostname; /* hostname portion of UNC string */ struct socket *ssocket; @@ -1785,7 +1786,7 @@ require use of the stronger protocol */ * list operations on pending_mid_q and oplockQ * updates to XID counters, multiplex id and SMB sequence numbers * list operations on global DnotifyReqList - * updates to ses->status + * updates to ses->status and TCP_Server_Info->tcpStatus * updates to server->CurrentMid * tcp_ses_lock protects: * list operations on tcp and SMB session lists diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 5d269f583dac..944fb92f50c7 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1358,7 +1358,9 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx) * to the struct since the kernel thread not created yet * no need to spinlock this init of tcpStatus or srv_count */ + spin_lock(&GlobalMid_Lock); tcp_ses->tcpStatus = CifsNew; + spin_unlock(&GlobalMid_Lock); ++tcp_ses->srv_count; if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN && @@ -1403,7 +1405,9 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx) goto out_err_crypto_release; } tcp_ses->min_offload = ctx->min_offload; + spin_lock(&GlobalMid_Lock); tcp_ses->tcpStatus = CifsNeedNegotiate; + spin_unlock(&GlobalMid_Lock); if ((ctx->max_credits < 20) || (ctx->max_credits > 60000)) tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE; diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index f65f9a692ca2..75a95de320cf 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -431,7 +431,9 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, * be taken as the remainder of this one. We need to kill the * socket so the server throws away the partial SMB */ + spin_lock(&GlobalMid_Lock); server->tcpStatus = CifsNeedReconnect; + spin_unlock(&GlobalMid_Lock); trace_smb3_partial_send_reconnect(server->CurrentMid, server->conn_id, server->hostname); } -- 2.30.2