Mercurial > hg > nginx-quic
view src/event/ngx_event_mutex.c @ 4964:2464ccebdb52
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.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 13 Dec 2012 16:05:59 +0000 |
parents | d620f497c50f |
children | 3377f9459e99 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ngx_int_t ngx_event_mutex_timedlock(ngx_event_mutex_t *m, ngx_msec_t timer, ngx_event_t *ev) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "lock event mutex %p lock:%XD", m, m->lock); if (m->lock) { if (m->events == NULL) { m->events = ev; } else { m->last->next = ev; } m->last = ev; ev->next = NULL; #if (NGX_THREADS0) ev->light = 1; #endif ngx_add_timer(ev, timer); return NGX_AGAIN; } m->lock = 1; return NGX_OK; } ngx_int_t ngx_event_mutex_unlock(ngx_event_mutex_t *m, ngx_log_t *log) { ngx_event_t *ev; if (m->lock == 0) { ngx_log_error(NGX_LOG_ALERT, log, 0, "tring to unlock the free event mutex %p", m); return NGX_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, log, 0, "unlock event mutex %p, next event: %p", m, m->events); m->lock = 0; if (m->events) { ev = m->events; m->events = ev->next; ev->next = (ngx_event_t *) ngx_posted_events; ngx_posted_events = ev; } return NGX_OK; }