Mercurial > hg > nginx
view src/http/modules/ngx_http_mirror_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 | 230d16d35ebc |
children |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_array_t *mirror; ngx_flag_t request_body; } ngx_http_mirror_loc_conf_t; typedef struct { ngx_int_t status; } ngx_http_mirror_ctx_t; static ngx_int_t ngx_http_mirror_handler(ngx_http_request_t *r); static void ngx_http_mirror_body_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_mirror_handler_internal(ngx_http_request_t *r); static void *ngx_http_mirror_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_mirror_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static char *ngx_http_mirror(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_int_t ngx_http_mirror_init(ngx_conf_t *cf); static ngx_command_t ngx_http_mirror_commands[] = { { ngx_string("mirror"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_mirror, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("mirror_request_body"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_mirror_loc_conf_t, request_body), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_mirror_module_ctx = { NULL, /* preconfiguration */ ngx_http_mirror_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_mirror_create_loc_conf, /* create location configuration */ ngx_http_mirror_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_mirror_module = { NGX_MODULE_V1, &ngx_http_mirror_module_ctx, /* module context */ ngx_http_mirror_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_http_mirror_handler(ngx_http_request_t *r) { ngx_int_t rc; ngx_http_mirror_ctx_t *ctx; ngx_http_mirror_loc_conf_t *mlcf; if (r != r->main) { return NGX_DECLINED; } mlcf = ngx_http_get_module_loc_conf(r, ngx_http_mirror_module); if (mlcf->mirror == NULL) { return NGX_DECLINED; } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "mirror handler"); if (mlcf->request_body) { ctx = ngx_http_get_module_ctx(r, ngx_http_mirror_module); if (ctx) { return ctx->status; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_mirror_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ctx->status = NGX_DONE; ngx_http_set_ctx(r, ctx, ngx_http_mirror_module); rc = ngx_http_read_client_request_body(r, ngx_http_mirror_body_handler); if (rc >= NGX_HTTP_SPECIAL_RESPONSE) { return rc; } ngx_http_finalize_request(r, NGX_DONE); return NGX_DONE; } return ngx_http_mirror_handler_internal(r); } static void ngx_http_mirror_body_handler(ngx_http_request_t *r) { ngx_http_mirror_ctx_t *ctx; ctx = ngx_http_get_module_ctx(r, ngx_http_mirror_module); ctx->status = ngx_http_mirror_handler_internal(r); r->preserve_body = 1; r->write_event_handler = ngx_http_core_run_phases; ngx_http_core_run_phases(r); } static ngx_int_t ngx_http_mirror_handler_internal(ngx_http_request_t *r) { ngx_str_t *name; ngx_uint_t i; ngx_http_request_t *sr; ngx_http_mirror_loc_conf_t *mlcf; mlcf = ngx_http_get_module_loc_conf(r, ngx_http_mirror_module); name = mlcf->mirror->elts; for (i = 0; i < mlcf->mirror->nelts; i++) { if (ngx_http_subrequest(r, &name[i], &r->args, &sr, NULL, NGX_HTTP_SUBREQUEST_BACKGROUND) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } sr->header_only = 1; sr->method = r->method; sr->method_name = r->method_name; } return NGX_DECLINED; } static void * ngx_http_mirror_create_loc_conf(ngx_conf_t *cf) { ngx_http_mirror_loc_conf_t *mlcf; mlcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_mirror_loc_conf_t)); if (mlcf == NULL) { return NULL; } mlcf->mirror = NGX_CONF_UNSET_PTR; mlcf->request_body = NGX_CONF_UNSET; return mlcf; } static char * ngx_http_mirror_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_mirror_loc_conf_t *prev = parent; ngx_http_mirror_loc_conf_t *conf = child; ngx_conf_merge_ptr_value(conf->mirror, prev->mirror, NULL); ngx_conf_merge_value(conf->request_body, prev->request_body, 1); return NGX_CONF_OK; } static char * ngx_http_mirror(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_mirror_loc_conf_t *mlcf = conf; ngx_str_t *value, *s; value = cf->args->elts; if (ngx_strcmp(value[1].data, "off") == 0) { if (mlcf->mirror != NGX_CONF_UNSET_PTR) { return "is duplicate"; } mlcf->mirror = NULL; return NGX_CONF_OK; } if (mlcf->mirror == NULL) { return "is duplicate"; } if (mlcf->mirror == NGX_CONF_UNSET_PTR) { mlcf->mirror = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t)); if (mlcf->mirror == NULL) { return NGX_CONF_ERROR; } } s = ngx_array_push(mlcf->mirror); if (s == NULL) { return NGX_CONF_ERROR; } *s = value[1]; return NGX_CONF_OK; } static ngx_int_t ngx_http_mirror_init(ngx_conf_t *cf) { ngx_http_handler_pt *h; ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); h = ngx_array_push(&cmcf->phases[NGX_HTTP_PRECONTENT_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_mirror_handler; return NGX_OK; }