Fixes an aliasing bug in opus_packet_pad()

Trying to add padding in-place breaks when we have extensions,
which causes a memcpy() with overlapping data. Just doing a
copy instead.
This commit is contained in:
Jean-Marc Valin 2024-02-20 14:23:59 -05:00
parent ecc10d835d
commit d9d0e7292f
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GPG key ID: 5E5DD9A36F9189C8

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@ -121,7 +121,7 @@ opus_int32 opus_repacketizer_out_range_impl(OpusRepacketizer *rp, int begin, int
int ext_begin=0, ext_len=0;
int ext_count, total_ext_count;
VARDECL(opus_extension_data, all_extensions);
ALLOC_STACK;
SAVE_STACK;
if (begin<0 || begin>=end || end>rp->nb_frames)
{
@ -312,6 +312,7 @@ opus_int32 opus_repacketizer_out_range_impl(OpusRepacketizer *rp, int begin, int
while (ptr<data+maxlen)
*ptr++=0;
}
RESTORE_STACK;
return tot_size;
}
@ -329,24 +330,32 @@ opus_int32 opus_packet_pad_impl(unsigned char *data, opus_int32 len, opus_int32
{
OpusRepacketizer rp;
opus_int32 ret;
VARDECL(unsigned char, copy);
SAVE_STACK;
if (len < 1)
return OPUS_BAD_ARG;
if (len==new_len)
return OPUS_OK;
else if (len > new_len)
return OPUS_BAD_ARG;
ALLOC(copy, len, unsigned char);
opus_repacketizer_init(&rp);
/* Moving payload to the end of the packet so we can do in-place padding */
OPUS_MOVE(data+new_len-len, data, len);
ret = opus_repacketizer_cat(&rp, data+new_len-len, len);
OPUS_COPY(copy, data, len);
ret = opus_repacketizer_cat(&rp, copy, len);
if (ret != OPUS_OK)
return ret;
return opus_repacketizer_out_range_impl(&rp, 0, rp.nb_frames, data, new_len, 0, pad, extensions, nb_extensions);
ret = opus_repacketizer_out_range_impl(&rp, 0, rp.nb_frames, data, new_len, 0, pad, extensions, nb_extensions);
RESTORE_STACK;
return ret;
}
int opus_packet_pad(unsigned char *data, opus_int32 len, opus_int32 new_len)
{
opus_int32 ret = opus_packet_pad_impl(data, len, new_len, 1, NULL, 0);
opus_int32 ret;
ALLOC_STACK;
ret = opus_packet_pad_impl(data, len, new_len, 1, NULL, 0);
RESTORE_STACK;
if (ret > 0)
return OPUS_OK;
else