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FAILED: patch "[PATCH] Handle mismatched open calls" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Apr 10, 2017 Stable branch

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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 38bd49064a1ecb67baad33598e3d824448ab11ec Mon Sep 17 00:00:00 2001

From: Sachin Prabhu <[email protected]>
Date: Fri, 3 Mar 2017 15:41:38 -0800
Subject: [PATCH] Handle mismatched open calls

A signal can interrupt a SendReceive call which result in incoming responses to the call being ignored. This is a problem for calls such as open which results in the successful response being ignored. This results in an open file resource on the server.

The patch looks into responses which were cancelled after being sent and in case of successful open closes the open fids.

For this patch, the check is only done in SendReceive2()

RH-bz: 1403319

fs/cifs/cifsglob.h +11 -0
index d42dd3288647..c34bdb12c8e6 100644
@@ -243,6 +243,7 @@ struct smb_version_operations {
 	/* verify the message */
 	int (*check_message)(char *, unsigned int, struct TCP_Server_Info *);
 	bool (*is_oplock_break)(char *, struct TCP_Server_Info *);
+	int (*handle_cancelled_mid)(char *, struct TCP_Server_Info *);
 	void (*downgrade_oplock)(struct TCP_Server_Info *,
 					struct cifsInodeInfo *, bool);
 	/* process transaction2 response */
@@ -1343,6 +1344,7 @@ struct mid_q_entry {
 	void *callback_data;	  /* general purpose pointer for callback */
 	void *resp_buf;		/* pointer to received SMB header */
 	int mid_state;	/* wish this were enum but can not pass to wait_event */
+	unsigned int mid_flags;
 	__le16 command;		/* smb command code */
 	bool large_buf:1;	/* if valid response, is pointer to large buf */
 	bool multiRsp:1;	/* multiple trans2 responses for one request  */
@@ -1350,6 +1352,12 @@ struct mid_q_entry {
 	bool decrypted:1;	/* decrypted entry */
 };
 
+struct close_cancelled_open {
+	struct cifs_fid         fid;
+	struct cifs_tcon        *tcon;
+	struct work_struct      work;
+};
+
 /*	Make code in transport.c a little cleaner by moving
 	update of optional stats into function below */
 #ifdef CONFIG_CIFS_STATS2
@@ -1481,6 +1489,9 @@ static inline void free_dfs_info_array(struct dfs_info3_param *param,
 #define   MID_RESPONSE_MALFORMED 0x10
 #define   MID_SHUTDOWN		 0x20
 
+/* Flags */
+#define   MID_WAIT_CANCELLED	 1 /* Cancelled while waiting for response */
+
 /* Types of response buffer returned from SendReceive2 */
 #define   CIFS_NO_BUFFER        0    /* Response buffer not returned */
 #define   CIFS_SMALL_BUFFER     1
fs/cifs/cifsproto.h +2 -1
index 97e5d236d265..ec5e5e514fdd 100644
@@ -79,7 +79,8 @@ extern void cifs_delete_mid(struct mid_q_entry *mid);
 extern void cifs_wake_up_task(struct mid_q_entry *mid);
 extern int cifs_handle_standard(struct TCP_Server_Info *server,
 				struct mid_q_entry *mid);
-extern int cifs_discard_remaining_data(struct TCP_Server_Info *server);
+extern int cifs_discard_remaining_data(struct TCP_Server_Info *server,
+				       char *buf);
 extern int cifs_call_async(struct TCP_Server_Info *server,
 			struct smb_rqst *rqst,
 			mid_receive_t *receive, mid_callback_t *callback,
fs/cifs/cifssmb.c +7 -4
index 066950671929..967b92631807 100644
@@ -1400,9 +1400,9 @@ CIFS_open(const unsigned int xid, struct cifs_open_parms *oparms, int *oplock,
  * current bigbuf.
  */
 int
-cifs_discard_remaining_data(struct TCP_Server_Info *server)
+cifs_discard_remaining_data(struct TCP_Server_Info *server, char *buf)
 {
-	unsigned int rfclen = get_rfc1002_length(server->smallbuf);
+	unsigned int rfclen = get_rfc1002_length(buf);
 	int remaining = rfclen + 4 - server->total_read;
 
 	while (remaining > 0) {
@@ -1426,7 +1426,7 @@ cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	int length;
 	struct cifs_readdata *rdata = mid->callback_data;
 
-	length = cifs_discard_remaining_data(server);
+	length = cifs_discard_remaining_data(server, mid->resp_buf);
 	dequeue_mid(mid, rdata->result);
 	return length;
 }
@@ -1459,7 +1459,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 
 	if (server->ops->is_status_pending &&
 	    server->ops->is_status_pending(buf, server, 0)) {
-		cifs_discard_remaining_data(server);
+		cifs_discard_remaining_data(server, buf);
 		return -1;
 	}
 
@@ -1519,6 +1519,9 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	cifs_dbg(FYI, "0: iov_base=%p iov_len=%u\n",
 		 rdata->iov[0].iov_base, server->total_read);
 
+	mid->resp_buf = server->smallbuf;
+	server->smallbuf = NULL;
+
 	/* how much data is in the response? */
 	data_len = server->ops->read_data_length(buf);
 	if (data_offset + data_len > buflen) {
fs/cifs/connect.c +11 -2
index 9ae695ae3ed7..0c7596cef4b8 100644
@@ -904,10 +904,19 @@ cifs_demultiplex_thread(void *p)
 
 		server->lstrp = jiffies;
 		if (mid_entry != NULL) {
+			if ((mid_entry->mid_flags & MID_WAIT_CANCELLED) &&
+			     mid_entry->mid_state == MID_RESPONSE_RECEIVED &&
+					server->ops->handle_cancelled_mid)
+				server->ops->handle_cancelled_mid(
+							mid_entry->resp_buf,
+							server);
+
 			if (!mid_entry->multiRsp || mid_entry->multiEnd)
 				mid_entry->callback(mid_entry);
-		} else if (!server->ops->is_oplock_break ||
-			   !server->ops->is_oplock_break(buf, server)) {
+		} else if (server->ops->is_oplock_break &&
+			   server->ops->is_oplock_break(buf, server)) {
+			cifs_dbg(FYI, "Received oplock break\n");
+		} else {
 			cifs_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
 				 atomic_read(&midCount));
 			cifs_dump_mem("Received Data is: ", buf,
fs/cifs/smb2misc.c +46 -0

49 lines not on this page · raw message

fs/cifs/smb2ops.c +6 -2
index 0231108d9387..b6bdf93042eb 100644
@@ -2188,7 +2188,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
 	if (rc)
 		goto free_pages;
 
-	rc = cifs_discard_remaining_data(server);
+	rc = cifs_discard_remaining_data(server, buf);
 	if (rc)
 		goto free_pages;
 
@@ -2214,7 +2214,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
 	kfree(pages);
 	return rc;
 discard_data:
-	cifs_discard_remaining_data(server);
+	cifs_discard_remaining_data(server, buf);
 	goto free_pages;
 }
 
@@ -2322,6 +2322,7 @@ struct smb_version_operations smb20_operations = {
 	.clear_stats = smb2_clear_stats,
 	.print_stats = smb2_print_stats,
 	.is_oplock_break = smb2_is_valid_oplock_break,
+	.handle_cancelled_mid = smb2_handle_cancelled_mid,
 	.downgrade_oplock = smb2_downgrade_oplock,
 	.need_neg = smb2_need_neg,
 	.negotiate = smb2_negotiate,
@@ -2404,6 +2405,7 @@ struct smb_version_operations smb21_operations = {
 	.clear_stats = smb2_clear_stats,
 	.print_stats = smb2_print_stats,
 	.is_oplock_break = smb2_is_valid_oplock_break,
+	.handle_cancelled_mid = smb2_handle_cancelled_mid,
 	.downgrade_oplock = smb2_downgrade_oplock,
 	.need_neg = smb2_need_neg,
 	.negotiate = smb2_negotiate,
@@ -2488,6 +2490,7 @@ struct smb_version_operations smb30_operations = {
 	.print_stats = smb2_print_stats,
 	.dump_share_caps = smb2_dump_share_caps,
 	.is_oplock_break = smb2_is_valid_oplock_break,
+	.handle_cancelled_mid = smb2_handle_cancelled_mid,
 	.downgrade_oplock = smb2_downgrade_oplock,
 	.need_neg = smb2_need_neg,
 	.negotiate = smb2_negotiate,
@@ -2582,6 +2585,7 @@ struct smb_version_operations smb311_operations = {
 	.print_stats = smb2_print_stats,
 	.dump_share_caps = smb2_dump_share_caps,
 	.is_oplock_break = smb2_is_valid_oplock_break,
+	.handle_cancelled_mid = smb2_handle_cancelled_mid,
 	.downgrade_oplock = smb2_downgrade_oplock,
 	.need_neg = smb2_need_neg,
 	.negotiate = smb2_negotiate,
fs/cifs/smb2proto.h +7 -0
index 69e35873b1de..6853454fc871 100644
@@ -48,6 +48,10 @@ extern struct mid_q_entry *smb2_setup_request(struct cifs_ses *ses,
 			      struct smb_rqst *rqst);
 extern struct mid_q_entry *smb2_setup_async_request(
 			struct TCP_Server_Info *server, struct smb_rqst *rqst);
+extern struct cifs_ses *smb2_find_smb_ses(struct TCP_Server_Info *server,
+					   __u64 ses_id);
+extern struct cifs_tcon *smb2_find_smb_tcon(struct TCP_Server_Info *server,
+						__u64 ses_id, __u32  tid);
 extern int smb2_calc_signature(struct smb_rqst *rqst,
 				struct TCP_Server_Info *server);
 extern int smb3_calc_signature(struct smb_rqst *rqst,
@@ -164,6 +168,9 @@ extern int SMB2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
 extern int SMB2_oplock_break(const unsigned int xid, struct cifs_tcon *tcon,
 			     const u64 persistent_fid, const u64 volatile_fid,
 			     const __u8 oplock_level);
+extern int smb2_handle_cancelled_mid(char *buffer,
+					struct TCP_Server_Info *server);
+void smb2_cancelled_close_fid(struct work_struct *work);
 extern int SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon,
 			 u64 persistent_file_id, u64 volatile_file_id,
 			 struct kstatfs *FSData);
fs/cifs/smb2transport.c +51 -4

74 lines not on this page · raw message

fs/cifs/transport.c +2 -0
index 526f0533cb4e..f6e13a977fc8 100644
@@ -752,9 +752,11 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	rc = wait_for_response(ses->server, midQ);
 	if (rc != 0) {
+		cifs_dbg(FYI, "Cancelling wait for mid %llu\n",	midQ->mid);
 		send_cancel(ses->server, rqst, midQ);
 		spin_lock(&GlobalMid_Lock);
 		if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
+			midQ->mid_flags |= MID_WAIT_CANCELLED;
 			midQ->callback = DeleteMidQEntry;
 			spin_unlock(&GlobalMid_Lock);
 			add_credits(ses->server, 1, optype);