Mercurial > hg > nginx-quic
view src/event/ngx_event_posted.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 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ngx_thread_volatile ngx_event_t *ngx_posted_accept_events; ngx_thread_volatile ngx_event_t *ngx_posted_events; #if (NGX_THREADS) ngx_mutex_t *ngx_posted_events_mutex; #endif void ngx_event_process_posted(ngx_cycle_t *cycle, ngx_thread_volatile ngx_event_t **posted) { ngx_event_t *ev; for ( ;; ) { ev = (ngx_event_t *) *posted; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p", ev); if (ev == NULL) { return; } ngx_delete_posted_event(ev); ev->handler(ev); } } #if (NGX_THREADS) && !(NGX_WIN32) void ngx_wakeup_worker_thread(ngx_cycle_t *cycle) { ngx_int_t i; #if 0 ngx_uint_t busy; ngx_event_t *ev; busy = 1; if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) { return; } for (ev = (ngx_event_t *) ngx_posted_events; ev; ev = ev->next) { if (*(ev->lock) == 0) { busy = 0; break; } } ngx_mutex_unlock(ngx_posted_events_mutex); if (busy) { return; } #endif for (i = 0; i < ngx_threads_n; i++) { if (ngx_threads[i].state == NGX_THREAD_FREE) { ngx_cond_signal(ngx_threads[i].cv); return; } } } ngx_int_t ngx_event_thread_process_posted(ngx_cycle_t *cycle) { ngx_event_t *ev; for ( ;; ) { ev = (ngx_event_t *) ngx_posted_events; for ( ;; ) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p", ev); if (ev == NULL) { return NGX_OK; } if (ngx_trylock(ev->lock) == 0) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p is busy", ev); ev = ev->next; continue; } if (ev->lock != ev->own_lock) { if (*(ev->own_lock)) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "the own lock of the posted event %p is busy", ev); ngx_unlock(ev->lock); ev = ev->next; continue; } *(ev->own_lock) = 1; } ngx_delete_posted_event(ev); ev->locked = 1; ev->ready |= ev->posted_ready; ev->timedout |= ev->posted_timedout; ev->pending_eof |= ev->posted_eof; #if (NGX_HAVE_KQUEUE) ev->kq_errno |= ev->posted_errno; #endif if (ev->posted_available) { ev->available = ev->posted_available; } ev->posted_ready = 0; ev->posted_timedout = 0; ev->posted_eof = 0; #if (NGX_HAVE_KQUEUE) ev->posted_errno = 0; #endif ev->posted_available = 0; ngx_mutex_unlock(ngx_posted_events_mutex); ev->handler(ev); ngx_mutex_lock(ngx_posted_events_mutex); if (ev->locked) { ngx_unlock(ev->lock); if (ev->lock != ev->own_lock) { ngx_unlock(ev->own_lock); } } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p is done", ev); break; } } } #else void ngx_wakeup_worker_thread(ngx_cycle_t *cycle) { } #endif