view src/os/unix/ngx_sunpro_x86.il @ 9322:d6f75dd66761 default tip

Mp4: added and updated sanity checks for "end" handling. When handling incorrect data in ngx_http_mp4_crop_stsc_data(), trak->end_chunk_samples might end up being arbitrary large, leading to reading before the buffer in ngx_http_mp4_update_stsz_atom(). Fix is to check that trak->end_chunk_samples corresponds to a memory within the stsz atom data. For consistency, trak->start_chunk_samples is checked similarly. Similarly, trak->end_chunk might end up being smaller than trak->start_chunk, leading to reading memory after the buffer in ngx_http_mp4_update_stco_atom() and ngx_http_mp4_update_co64_atom(). Corresponding checks are updated to explicitly test (trak->end_chunk - trak->start_chunk) instead of just checking trak->end_chunk and assuming it is larger than trak->start_chunk. This is generally in line with existing checks of (trak->end_sample - trak->start_sample) in ngx_http_mp4_update_stsz_atom(), where trak->end_sample might also become smaller than trak->start_sample when handling incorrect data in ngx_http_mp4_crop_stts_data().
author Maxim Dounin <mdounin@mdounin.ru>
date Sun, 25 Aug 2024 06:35:40 +0300
parents 2cd019520210
children
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/
/ Copyright (C) Igor Sysoev
/ Copyright (C) Nginx, Inc.
/

/ ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
/     ngx_atomic_uint_t old, ngx_atomic_uint_t set);
/
/ the arguments are passed on stack (%esp), 4(%esp), 8(%esp)

        .inline ngx_atomic_cmp_set,0
        movl      (%esp), %ecx
        movl      4(%esp), %eax
        movl      8(%esp), %edx
        lock
        cmpxchgl  %edx, (%ecx)
        setz      %al
        movzbl    %al, %eax
        .end


/ ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value,
/     ngx_atomic_int_t add);
/
/ the arguments are passed on stack (%esp), 4(%esp)

        .inline ngx_atomic_fetch_add,0
        movl      (%esp), %ecx
        movl      4(%esp), %eax
        lock
        xaddl     %eax, (%ecx)
        .end


/ ngx_cpu_pause()
/
/ the "rep; nop" is used instead of "pause" to avoid the "[ PAUSE ]" hardware
/ capability added by linker because Solaris/i386 does not know about it:
/
/ ld.so.1: nginx: fatal: hardware capability unsupported: 0x2000  [ PAUSE ]

        .inline ngx_cpu_pause,0
        rep; nop
        .end