uhttpd: fix crashes in the ubus plugin

The ubus plugin calls blocking ubus functions that loop back into
uloop_run. Protect the client data structure with refcounting to ensure
that the outer uloop_run call does not clean up the data that the inner
uloop_run call is still processing.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/utils.c b/utils.c
index 3b868e3..b1d7d37 100644
--- a/utils.c
+++ b/utils.c
@@ -35,6 +35,9 @@ void uh_chunk_write(struct client *cl, const void *data, int len)
 {
 	bool chunked = uh_use_chunked(cl);
 
+	if (cl->state == CLIENT_STATE_CLEANUP)
+		return;
+
 	uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 	if (chunked)
 		ustream_printf(cl->us, "%X\r\n", len);
@@ -49,6 +52,9 @@ void uh_chunk_vprintf(struct client *cl, const char *format, va_list arg)
 	va_list arg2;
 	int len;
 
+	if (cl->state == CLIENT_STATE_CLEANUP)
+		return;
+
 	uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 	if (!uh_use_chunked(cl)) {
 		ustream_vprintf(cl->us, format, arg);
@@ -81,6 +87,9 @@ void uh_chunk_eof(struct client *cl)
 	if (!uh_use_chunked(cl))
 		return;
 
+	if (cl->state == CLIENT_STATE_CLEANUP)
+		return;
+
 	ustream_printf(cl->us, "0\r\n\r\n");
 }