[PATCH v2 06/11] serve: drop "keys" strvec

From: Jeff King <peff@peff.net>
Date: Sep 14, 2021, 23:51 UTC
Message-ID: <YUE1hExkU9V12iZv@coredump.intra.peff.net>
In-Reply-To: <YUE1alo58cGyTw6/@coredump.intra.peff.net>

We collect the set of capabilities the client sends us in a strvec. While this is usually small, there's no limit to the number of capabilities the client can send us (e.g., they could just send us "agent" pkt-lines over and over, and we'd keep adding them to the list).

Since all code has been converted away from using this list, let's get rid of it. This avoids a potential attack where clients waste our memory.

Note that we do have to replace it with a flag, because some of the flush-packet logic checks whether we've seen any valid commands or keys.

Signed-off-by: Jeff King <peff@peff.net>
---
 serve.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/serve.c b/serve.c
index 6bbf54cbbe..5ea6c915cb 100644
--- a/serve.c
+++ b/serve.c
@@ -239,7 +239,7 @@ static int process_request(void)
 {
 	enum request_state state = PROCESS_REQUEST_KEYS;
 	struct packet_reader reader;
-	struct strvec keys = STRVEC_INIT;
+	int seen_capability_or_command = 0;
 	struct protocol_capability *command = NULL;
 
 	packet_reader_init(&reader, 0, NULL, 0,
@@ -263,7 +263,7 @@ static int process_request(void)
 			/* collect request; a sequence of keys and values */
 			if (parse_command(reader.line, &command) ||
 			    receive_client_capability(reader.line))
-				strvec_push(&keys, reader.line);
+				seen_capability_or_command = 1;
 			else
 				die("unknown capability '%s'", reader.line);
 
@@ -275,7 +275,7 @@ static int process_request(void)
 			 * If no command and no keys were given then the client
 			 * wanted to terminate the connection.
 			 */
-			if (!keys.nr)
+			if (!seen_capability_or_command)
 				return 1;
 
 			/*
@@ -309,7 +309,6 @@ static int process_request(void)
 
 	command->command(the_repository, &reader);
 
-	strvec_clear(&keys);
 	return 0;
 }

-- 
2.33.0.917.gae6ecbedc7