From 16f4851c139b73b3d143d6747350509db1aae15c Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Thu, 13 Dec 2012 16:05:59 +0000 Subject: [PATCH] Upstream: fixed SIGSEGV with the "if" directive. Configuration like location / { set $true 1; if ($true) { proxy_pass http://backend; } if ($true) { # nothing } } resulted in segmentation fault due to NULL pointer dereference as the upstream configuration wasn't initialized in an implicit location created by the last if(), but the r->content_handler was set due to first if(). Instead of committing a suicide by dereferencing a NULL pointer, return 500 (Internal Server Error) in such cases, i.e. if uscf is NULL. Better fix would be to avoid such cases by fixing the "if" directive handling, but it's out of scope of this patch. Prodded by Piotr Sikora. --- src/http/ngx_http_upstream.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c index 703017f54..5e04324d7 100644 --- a/src/http/ngx_http_upstream.c +++ b/src/http/ngx_http_upstream.c @@ -636,6 +636,14 @@ ngx_http_upstream_init_request(ngx_http_request_t *r) found: + if (uscf == NULL) { + ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, + "no upstream configuration"); + ngx_http_upstream_finalize_request(r, u, + NGX_HTTP_INTERNAL_SERVER_ERROR); + return; + } + if (uscf->peer.init(r, uscf) != NGX_OK) { ngx_http_upstream_finalize_request(r, u, NGX_HTTP_INTERNAL_SERVER_ERROR);