Commit 0a49fe77 authored by Max Kellermann's avatar Max Kellermann Committed by Erik de Castro Lopo

stream_decoder: check state==ABORTED after process_single() for seek

FLAC__stream_decoder_process_single() ignores frame_sync_() errors,
which means the caller cannot rely solely on the boolean return value,
it is also required to check the new "state".

After FLAC__stream_decoder_process_until_end_of_metadata(),
state==SEARCH_FOR_FRAME_SYNC and
last_frame.header.number_type==FRAME_NUMBER.  When an application
seeks at this time, but an I/O error occurs, then
FLAC__stream_decoder_process_single() returns true, but no frame has
been read yet, i.e. last_frame.header.number_type is still
FRAME_NUMBER.  This triggers the assertion in
seek_to_absolute_sample_():

 FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);

So what needs to be done is check for state==ABORTED after the
FLAC__stream_decoder_process_single() call.

This bug can be triggered remotely with the Music Player Daemon
(https://www.musicpd.org/), and crashes the process.
Signed-off-by: Erik de Castro Lopo's avatarErik de Castro Lopo <erikd@mega-nerd.com>
Closes: https://github.com/xiph/flac/pull/12
parent 82797787
......@@ -3134,7 +3134,8 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
* FLAC__stream_decoder_process_single() to return false.
*/
decoder->private_->unparseable_frame_count = 0;
if(!FLAC__stream_decoder_process_single(decoder)) {
if(!FLAC__stream_decoder_process_single(decoder) ||
decoder->protected_->state == FLAC__STREAM_DECODER_ABORTED) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
......@@ -3261,7 +3262,8 @@ FLAC__bool seek_to_absolute_sample_ogg_(FLAC__StreamDecoder *decoder, FLAC__uint
did_a_seek = false;
decoder->private_->got_a_frame = false;
if(!FLAC__stream_decoder_process_single(decoder)) {
if(!FLAC__stream_decoder_process_single(decoder) ||
decoder->protected_->state == FLAC__STREAM_DECODER_ABORTED) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
......
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