[FFmpeg-devel] [PR] avcodec/golomb: Fix get_ur_golomb_jpegls() with esclen = 0 (PR #21782)

[FFmpeg-devel] [PR] avcodec/golomb: Fix get_ur_golomb_jpegls() with esclen = 0 (PR #21782)

[michaelni via ffmpeg-devel]

PR #21782 opened by michaelni
URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21782
Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21782.patch

If there is no escape case then reaching that branch is an error

Fixes: shift exponent 32 is too large for 32-bit type 'uint32_t' (aka 'unsigned int')
Fixes: 472335543/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DST_fuzzer-6682453243920384

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>


>From ed010c928ec25a0a14252968d497baa299c236f7 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sun, 15 Feb 2026 23:57:49 +0100
Subject: [PATCH] avcodec/golomb: Fix get_ur_golomb_jpegls() with esclen = 0

If there is no escape case then reaching that branch is an error

Fixes: shift exponent 32 is too large for 32-bit type 'uint32_t' (aka 'unsigned int')
Fixes: 472335543/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DST_fuzzer-6682453243920384

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/golomb.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
index 742334978d..5169a5a4c0 100644
--- a/libavcodec/golomb.h
+++ b/libavcodec/golomb.h
@@ -455,7 +455,7 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
             buf = get_bits_long(gb, k);
 
             return buf + (i << k);
-        } else if (i == limit - 1) {
+        } else if (esc_len && i == limit - 1) {
             buf = get_bits_long(gb, esc_len);
 
             return buf + 1;
@@ -512,7 +512,7 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
             }
 
             buf += ((SUINT)i << k);
-        } else if (i == limit - 1) {
+        } else if (esc_len && i == limit - 1) {
             buf = SHOW_UBITS(re, gb, esc_len);
             LAST_SKIP_BITS(re, gb, esc_len);
 
-- 
2.52.0

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