On 7/8/2024 2:24 PM, Andreas Rheinhardt wrote:
The check "left >= INT_MAX - right" is supposed to check for
whether left + right does not overflow/wraparound, but given that
left and top are uint32_t INT_MAX - right can already wraparound
for big values of right (and ordinary 32-bit ints):
If right == UINT32_MAX, INT_MAX - right is INT_MAX + 1;
for left in 0..par->width both checks will be passed.
Fix this and simplify the check by using 64-bit types,
where the addition is guaranteed not to overflow.
Signed-off-by: Andreas Rheinhardt <[email protected]>
---
libavformat/matroskaenc.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index e1adc0eba6..4b91283119 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -1786,16 +1786,14 @@ static int mkv_write_track_video(AVFormatContext *s,
MatroskaMuxContext *mkv,
st->codecpar->nb_coded_side_data,
AV_PKT_DATA_FRAME_CROPPING);
if (sd && sd->size == sizeof(uint32_t) * 4) {
- uint32_t top, bottom, left, right;
+ uint64_t top, bottom, left, right;
top = AV_RL32(sd->data + 0);
bottom = AV_RL32(sd->data + 4);
left = AV_RL32(sd->data + 8);
right = AV_RL32(sd->data + 12);
- if (left >= INT_MAX - right ||
- top >= INT_MAX - bottom ||
- (left + right) >= par->width ||
+ if ((left + right) >= par->width ||
(top + bottom) >= par->height) {
av_log(s, AV_LOG_ERROR, "Invalid cropping dimensions in stream side
data\n");
return AVERROR(EINVAL);
LGTM.
_______________________________________________
ffmpeg-devel mailing list
[email protected]
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
[email protected] with subject "unsubscribe".
