From a1db464c3e3db8dc1d378c10bd627b8a4d09ab7a Mon Sep 17 00:00:00 2001 From: Amaury Denoyelle Date: Fri, 6 Feb 2026 21:28:42 +0100 Subject: [PATCH] BUG/MINOR: proxy: fix null dereference in "add backend" handler When a backend is created at runtime, the new proxy instance is inserted at the end of proxies_list. This operation is buggy if this list is empty : the code causes a null dereference which will lead to a crash. This causes the following compilation error : CC src/proxy.o src/proxy.c: In function 'cli_parse_add_backend': src/proxy.c:4933:36: warning: null pointer dereference [-Wnull-dereference] 4933 | proxies_list->next = px; | ~~~~~~~~~~~~~~~~~~~^~~~ This patch fixes this issue. Note that in reality it cannot occur at this moment as proxies_list cannot be empty (haproxy requires at least one frontend to start, and the list also always contains internal proxies). No need to backport. --- src/proxy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/proxy.c b/src/proxy.c index 15a829187..3529085ee 100644 --- a/src/proxy.c +++ b/src/proxy.c @@ -4927,7 +4927,7 @@ static int cli_parse_add_backend(char **args, char *payload, struct appctx *appc dynpx_next_id = px->uuid; if (!proxies_list) { - proxies_list->next = px; + proxies_list = px; } else { for (next = proxies_list; next->next; next = next->next) -- 2.47.3