Mercurial > hg > nginx-quic
view src/misc/ngx_google_perftools_module.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | a27e0c7e198c |
children |
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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 */