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[FFmpeg-devel,6/6] avcodec/apedec: Use NABS to avoid undefined negation

Message ID 20240401205607.9093-6-michael@niedermayer.cc
State Accepted
Commit 1887ff250cfd1e69c08bca21cc53e30a39e26818
Headers show
Series [FFmpeg-devel,1/6] avformat/isom: Uninit layout in ff_mp4_read_dec_config_descr() | expand

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Commit Message

Michael Niedermayer April 1, 2024, 8:56 p.m. UTC 
Fixes: negation of -2147483648 cannot be represented in type 'int32_t' (aka 'int'); cast to an unsigned type to negate this value to itself
Fixes: 67738/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5444313212321792

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/apedec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Michael Niedermayer April 2, 2024, 9:25 p.m. UTC | #1 
On Mon, Apr 01, 2024 at 10:56:07PM +0200, Michael Niedermayer wrote:
> Fixes: negation of -2147483648 cannot be represented in type 'int32_t' (aka 'int'); cast to an unsigned type to negate this value to itself
> Fixes: 67738/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5444313212321792
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/apedec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

will apply

[...]
diff mbox series

Patch

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 86b79182a73..d75a85f4664 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -1287,7 +1287,7 @@  static void predictor_decode_stereo_3950(APEContext *ctx, int count)
                 int32_t left  = a1 - (unsigned)(a0 / 2);
                 int32_t right = left + (unsigned)a0;
 
-                if (FFMAX(FFABS(left), FFABS(right)) > (1<<23)) {
+                if (FFMIN(FFNABS(left), FFNABS(right)) < -(1<<23)) {
                     ctx->interim_mode = !interim_mode;
                     av_log(ctx->avctx, AV_LOG_VERBOSE, "Interim mode: %d\n", ctx->interim_mode);
                     break;