Mp4: fixed possible pointer overflow on 32-bit platforms. On 32-bit platforms mp4->buffer_pos might overflow when a large enough (close to 4 gigabytes) atom is being skipped, resulting in incorrect memory addesses being read further in the code. In most cases this results in harmless errors being logged, though may also result in a segmentation fault if hitting unmapped pages. To address this, ngx_mp4_atom_next() now only increments mp4->buffer_pos up to mp4->buffer_end. This ensures that overflow cannot happen.

/*
 * Copyright (C) Maxim Dounin
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


char *
ngx_dlerror(void)
{
    u_char         *p;
    static u_char   errstr[NGX_MAX_ERROR_STR];

    p = ngx_strerror(ngx_errno, errstr, NGX_MAX_ERROR_STR);
    *p = '\0';

    return (char *) errstr;
}