[CIFS] Do not send SMBEcho requests on new sockets until SMBNegotiate (7e90d705) · Commits · 戴 / test

In order to determine whether an SMBEcho request can be sent we need to know that the socket is established (server tcpStatus == CifsGood) AND that an SMB NegotiateProtocol has been sent (server maxBuf != 0). Without the second check we can send an Echo request during reconnection before the server can accept it. CC: JG <jg@cms.ac> Reviewed-by:

Jeff Layton <jlayton@redhat.com> Signed-off-by:

Steve French <sfrench@us.ibm.com>

fs/cifs/cifsglob.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -188,6 +188,8 @@ struct TCP_Server_Info {
		/* multiplexed reads or writes */
		unsigned int maxBuf; /* maxBuf specifies the maximum */
		/* message size the server can send or receive for non-raw SMBs */
		/* maxBuf is returned by SMB NegotiateProtocol so maxBuf is only 0 */
		/* when socket is setup (and during reconnect) before NegProt sent */
		unsigned int max_rw; /* maxRw specifies the maximum */
		/* message size the server can send or receive for */
		/* SMB_COM_WRITE_RAW or SMB_COM_READ_RAW. */

fs/cifs/connect.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -341,7 +341,7 @@ cifs_echo_request(struct work_struct *work)
		* We cannot send an echo until the NEGOTIATE_PROTOCOL request is done.
		* Also, no need to ping if we got a response recently
		*/
		if (server->tcpStatus != CifsGood \|\|
		if ((server->tcpStatus != CifsGood) \|\| (server->maxBuf == 0) \|\|
		time_before(jiffies, server->lstrp + SMB_ECHO_INTERVAL - HZ))
		goto requeue_echo;

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