From: Guus Sliepen <guus@meshlink.io>
Date: Wed, 20 May 2020 22:13:50 +0000 (+0200)
Subject: Limit the size of the fd read buffer in channel_poll().
X-Git-Url: http://git.meshlink.io/?p=meshlink;a=commitdiff_plain;h=f95981a276aa0dbd03f51190949fa8c5db74d8ff;hp=184155443a03b095155b210945a705b7f936cc4d

Limit the size of the fd read buffer in channel_poll().
---

diff --git a/src/meshlink.c b/src/meshlink.c
index 14ff7155..e50be188 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -3675,6 +3675,11 @@ static void channel_poll(struct utcp_connection *connection, size_t len) {
 		if(aio->data) {
 			sent = utcp_send(connection, (char *)aio->data + aio->done, todo);
 		} else {
+			/* Limit the amount we read at once to avoid stack overflows */
+			if(todo > 65536) {
+				todo = 65536;
+			}
+
 			char buf[todo];
 			ssize_t result = read(aio->fd, buf, todo);