[FFmpeg-devel] lavc/avpacket: forward av_buffer_realloc() error code.

Fix CID 1457229.

Signed-off-by: Nicolas George <george@nsup.org>
---
 libavcodec/avpacket.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Nicolas George:
> Fix CID 1457229.
> 
> Signed-off-by: Nicolas George <george@nsup.org>
> ---
>  libavcodec/avpacket.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> index 858f827a0a..4da832c53c 100644
> --- a/libavcodec/avpacket.c
> +++ b/libavcodec/avpacket.c
> @@ -170,7 +170,7 @@ FF_DISABLE_DEPRECATION_WARNINGS
>  #define ALLOC_MALLOC(data, size) data = av_malloc(size)
>  #define ALLOC_BUF(data, size)                \
>  do {                                         \
> -    av_buffer_realloc(&pkt->buf, size);      \
> +    ret = av_buffer_realloc(&pkt->buf, size);      \

You do not change the check, so the same comment as to your other
patch applies: Do you think that Coverity will think that this is a
real check? (I don't think so, otherwise it wouldn't have raised the
issue in the first place.)

>      data = pkt->buf ? pkt->buf->data : NULL; \
>  } while (0)
>  
> @@ -197,6 +197,8 @@ do {                                         \
>  /* Makes duplicates of data, side_data, but does not copy any other fields */
>  static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
>  {
> +    int ret = AVERROR_BUG;
> +
>      pkt->data      = NULL;
>      pkt->side_data = NULL;
>      pkt->side_data_elems = 0;
> @@ -220,7 +222,8 @@ static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
>  
>  failed_alloc:
>      av_packet_unref(pkt);
> -    return AVERROR(ENOMEM);
> +    av_assert1(ret != AVERROR_BUG);

There is an overflow check that could also trigger going to
failed_alloc. The overflow check is very weird: It is only triggered
if pkt->size is in the range -AV_INPUT_BUFFER_PADDING_SIZE..-1 and so
doesn't do its job (should be replaced by (unsigned)(size) > INT_MAX -
AV_INPUT_BUFFER_PADDING_SIZE). But if it were fixed, one could run
into this assert. How about initializing ret to 0 and setting ret to
AVERROR(ERANGE) if it is still zero in failed_alloc?

- Andreas

> +    return ret;
>  }
>  
>  int av_copy_packet_side_data(AVPacket *pkt, const AVPacket *src)
>

Nicolas George (12020-01-04):
> Fix CID 1457229.
> 
> Signed-off-by: Nicolas George <george@nsup.org>
> ---
>  libavcodec/avpacket.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)

Ping? Will apply next time I think about it if nobody objects and it
still applies.

Regards,

Nicolas George (12020-08-09):
> Ping? Will apply next time I think about it if nobody objects and it
> still applies.

Sorry, I missed Andreas comment in another mailbox.

Regards,

On 1/4/2020 4:00 PM, Nicolas George wrote:
> Fix CID 1457229.
> 
> Signed-off-by: Nicolas George <george@nsup.org>
> ---
>  libavcodec/avpacket.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> index 858f827a0a..4da832c53c 100644
> --- a/libavcodec/avpacket.c
> +++ b/libavcodec/avpacket.c
> @@ -170,7 +170,7 @@ FF_DISABLE_DEPRECATION_WARNINGS
>  #define ALLOC_MALLOC(data, size) data = av_malloc(size)
>  #define ALLOC_BUF(data, size)                \
>  do {                                         \
> -    av_buffer_realloc(&pkt->buf, size);      \
> +    ret = av_buffer_realloc(&pkt->buf, size);      \
>      data = pkt->buf ? pkt->buf->data : NULL; \
>  } while (0)
>  
> @@ -197,6 +197,8 @@ do {                                         \
>  /* Makes duplicates of data, side_data, but does not copy any other fields */
>  static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
>  {
> +    int ret = AVERROR_BUG;
> +
>      pkt->data      = NULL;
>      pkt->side_data = NULL;
>      pkt->side_data_elems = 0;
> @@ -220,7 +222,8 @@ static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
>  
>  failed_alloc:
>      av_packet_unref(pkt);
> -    return AVERROR(ENOMEM);
> +    av_assert1(ret != AVERROR_BUG);
> +    return ret;
>  }
>  
>  int av_copy_packet_side_data(AVPacket *pkt, const AVPacket *src)

This code is deprecated and will be removed in the next major bump, so
IMO it's worth trying to fix it, and especially if it's just to silence
a static analyzer.