[FFmpeg-cvslog] avcodec/hevc/hevcdec: ensure a bit was read when checking for alignment_bit_equal_to_one

[James Almer]

ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Fri May  2 16:26:04 2025 -0300| [d34c7384351a4aeb271b22a731e109c60356f068] | committer: James Almer

avcodec/hevc/hevcdec: ensure a bit was read when checking for alignment_bit_equal_to_one

Prevents printing bogus errors about the value being 0, when in fact we
overread the available slice buffer.

Signed-off-by: James Almer <jamrial at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d34c7384351a4aeb271b22a731e109c60356f068
---

 libavcodec/hevc/hevcdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
index 83acf3511f..df186d6194 100644
--- a/libavcodec/hevc/hevcdec.c
+++ b/libavcodec/hevc/hevcdec.c
@@ -1154,7 +1154,7 @@ static int hls_slice_header(SliceHeader *sh, const HEVCContext *s, GetBitContext
     }
 
     ret = get_bits1(gb);
-    if (!ret) {
+    if (!ret && get_bits_left(gb) >= 0) {
         av_log(s->avctx, AV_LOG_ERROR, "alignment_bit_equal_to_one=0\n");
         return AVERROR_INVALIDDATA;
     }