Mercurial > hg > nginx-quic
view src/core/ngx_list.h @ 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 | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_LIST_H_INCLUDED_ #define _NGX_LIST_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct ngx_list_part_s ngx_list_part_t; struct ngx_list_part_s { void *elts; ngx_uint_t nelts; ngx_list_part_t *next; }; typedef struct { ngx_list_part_t *last; ngx_list_part_t part; size_t size; ngx_uint_t nalloc; ngx_pool_t *pool; } ngx_list_t; ngx_list_t *ngx_list_create(ngx_pool_t *pool, ngx_uint_t n, size_t size); static ngx_inline ngx_int_t ngx_list_init(ngx_list_t *list, ngx_pool_t *pool, ngx_uint_t n, size_t size) { list->part.elts = ngx_palloc(pool, n * size); if (list->part.elts == NULL) { return NGX_ERROR; } list->part.nelts = 0; list->part.next = NULL; list->last = &list->part; list->size = size; list->nalloc = n; list->pool = pool; return NGX_OK; } /* * * the iteration through the list: * * part = &list.part; * data = part->elts; * * for (i = 0 ;; i++) { * * if (i >= part->nelts) { * if (part->next == NULL) { * break; * } * * part = part->next; * data = part->elts; * i = 0; * } * * ... data[i] ... * * } */ void *ngx_list_push(ngx_list_t *list); #endif /* _NGX_LIST_H_INCLUDED_ */