From dd8351b1184b8054925c28ecc5fcb6dbbc177fad Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Wed, 14 Feb 2018 13:01:46 +0100
Subject: [PATCH] avcodec/exr: Check remaining bits in last get code loop

Fixes: runtime error: shift exponent -7 is negative
Fixes: 3902/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EXR_fuzzer-6081926122176512

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

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index f08576af22..47f59bd638 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -558,7 +558,7 @@ static int huf_decode(const uint64_t *hcode, const HufDec *hdecod,
     while (lc > 0) {
         const HufDec pl = hdecod[(c << (HUF_DECBITS - lc)) & HUF_DECMASK];
 
-        if (pl.len) {
+        if (pl.len && lc >= pl.len) {
             lc -= pl.len;
             get_code(pl.lit, rlc, c, lc, gb, out, oe, outb);
         } else {