Mercurial > hg > nginx
view src/misc/ngx_google_perftools_module.c @ 7054:e02555553d0b
Range filter: protect from total size overflows.
The overflow can be used to circumvent the restriction on total size of
ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow
allows producing ranges with negative start (such ranges can be created
by using a suffix, "bytes=-100"; normally this results in 200 due to
the total size check). These can result in the following errors in logs:
[crit] ... pread() ... failed (22: Invalid argument)
[alert] ... sendfile() failed (22: Invalid argument)
When using cache, it can be also used to reveal cache file header.
It is believed that there are no other negative effects, at least with
standard nginx modules.
In theory, this can also result in memory disclosure and/or segmentation
faults if multiple ranges are allowed, and the response is returned in a
single in-memory buffer. This never happens with standard nginx modules
though, as well as known 3rd party modules.
Fix is to properly protect from possible overflow when incrementing size.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 11 Jul 2017 16:06:23 +0300 |
parents | d620f497c50f |
children | a27e0c7e198c |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> /* * declare Profiler interface here because * <google/profiler.h> is C++ header file */ int ProfilerStart(u_char* fname); void ProfilerStop(void); void ProfilerRegisterThread(void); static void *ngx_google_perftools_create_conf(ngx_cycle_t *cycle); static ngx_int_t ngx_google_perftools_worker(ngx_cycle_t *cycle); typedef struct { ngx_str_t profiles; } ngx_google_perftools_conf_t; static ngx_command_t ngx_google_perftools_commands[] = { { ngx_string("google_perftools_profiles"), NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, 0, offsetof(ngx_google_perftools_conf_t, profiles), NULL }, ngx_null_command }; static ngx_core_module_t ngx_google_perftools_module_ctx = { ngx_string("google_perftools"), ngx_google_perftools_create_conf, NULL }; ngx_module_t ngx_google_perftools_module = { NGX_MODULE_V1, &ngx_google_perftools_module_ctx, /* module context */ ngx_google_perftools_commands, /* module directives */ NGX_CORE_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ ngx_google_perftools_worker, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static void * ngx_google_perftools_create_conf(ngx_cycle_t *cycle) { ngx_google_perftools_conf_t *gptcf; gptcf = ngx_pcalloc(cycle->pool, sizeof(ngx_google_perftools_conf_t)); if (gptcf == NULL) { return NULL; } /* * set by ngx_pcalloc() * * gptcf->profiles = { 0, NULL }; */ return gptcf; } static ngx_int_t ngx_google_perftools_worker(ngx_cycle_t *cycle) { u_char *profile; ngx_google_perftools_conf_t *gptcf; gptcf = (ngx_google_perftools_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_google_perftools_module); if (gptcf->profiles.len == 0) { return NGX_OK; } profile = ngx_alloc(gptcf->profiles.len + NGX_INT_T_LEN + 2, cycle->log); if (profile == NULL) { return NGX_OK; } if (getenv("CPUPROFILE")) { /* disable inherited Profiler enabled in master process */ ProfilerStop(); } ngx_sprintf(profile, "%V.%d%Z", &gptcf->profiles, ngx_pid); if (ProfilerStart(profile)) { /* start ITIMER_PROF timer */ ProfilerRegisterThread(); } else { ngx_log_error(NGX_LOG_CRIT, cycle->log, ngx_errno, "ProfilerStart(%s) failed", profile); } ngx_free(profile); return NGX_OK; } /* ProfilerStop() is called on Profiler destruction */