Attachment 15153 Details for Bug 13930 – Patch for 4.9 and 4.10

[patch] Patch for 4.9 and 4.10

BZ13930.patch (text/plain), 2.47 KB, created by Martin Schwenke on 2019-05-15 02:11:12 UTC

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Creator: Martin Schwenke

Created: 2019-05-15 02:11:12 UTC

Size: 2.47 KB

patch

obsolete

>From e58d1dc4b685568f51c00506d81ab12b95be8d4a Mon Sep 17 00:00:00 2001
>From: Martin Schwenke <martin@meltin.net>
>Date: Mon, 6 May 2019 15:22:49 +1000
>Subject: [PATCH] ctdb-daemon: Never use 0 as a client ID
>
>ctdb_control_db_attach() and ctdb_control_db_detach() assume that any
>control with client ID 0 comes from another daemon and treat it
>specially.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=13930
>
>Signed-off-by: Martin Schwenke <martin@meltin.net>
>Reviewed-by: Amitay Isaacs <amitay@gmail.com>
>(cherry picked from commit 8663e0a64fbdb9ea16babbfe87d6f5d7a7b72bbd)
>---
> ctdb/server/ctdb_daemon.c | 48 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 47 insertions(+), 1 deletion(-)
>
>diff --git a/ctdb/server/ctdb_daemon.c b/ctdb/server/ctdb_daemon.c
>index a8691388d4a..aa0694548f8 100644
>--- a/ctdb/server/ctdb_daemon.c
>+++ b/ctdb/server/ctdb_daemon.c
>@@ -928,6 +928,44 @@ static int ctdb_clientpid_destructor(struct ctdb_client_pid_list *client_pid)
> 	return 0;
> }
> 
>+static int get_new_client_id(struct reqid_context *idr,
>+			     struct ctdb_client *client,
>+			     uint32_t *out)
>+{
>+	uint32_t client_id;
>+
>+	client_id = reqid_new(idr, client);
>+	/*
>+	 * Some places in the code (e.g. ctdb_control_db_attach(),
>+	 * ctdb_control_db_detach()) assign a special meaning to
>+	 * client_id 0.  The assumption is that if client_id is 0 then
>+	 * the control has come from another daemon.  Therefore, we
>+	 * should never return client_id == 0.
>+	 */
>+	if (client_id == 0) {
>+		/*
>+		 * Don't leak ID 0.  This is safe because the ID keeps
>+		 * increasing.  A test will be added to ensure that
>+		 * this doesn't change.
>+		 */
>+		reqid_remove(idr, 0);
>+
>+		client_id = reqid_new(idr, client);
>+	}
>+
>+	if (client_id == REQID_INVALID) {
>+		return EINVAL;
>+	}
>+
>+	if (client_id == 0) {
>+		/* Every other ID must have been used and we can't use 0 */
>+		reqid_remove(idr, 0);
>+		return EINVAL;
>+	}
>+
>+	*out = client_id;
>+	return 0;
>+}
> 
> static void ctdb_accept_client(struct tevent_context *ev,
> 			       struct tevent_fd *fde, uint16_t flags,
>@@ -971,7 +1009,15 @@ static void ctdb_accept_client(struct tevent_context *ev,
> 
> 	client->ctdb = ctdb;
> 	client->fd = fd;
>-	client->client_id = reqid_new(ctdb->idr, client);
>+
>+	ret = get_new_client_id(ctdb->idr, client, &client->client_id);
>+	if (ret != 0) {
>+		DBG_ERR("Unable to get client ID (%d)\n", ret);
>+		close(fd);
>+		talloc_free(client);
>+		return;
>+	}
>+
> 	client->pid = peer_pid;
> 
> 	client_pid = talloc(client, struct ctdb_client_pid_list);
>-- 
>2.20.1
>

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amitay: review+

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Attachments on bug 13930: 15153