From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id E9E57442B7 for ; Sat, 5 Nov 2022 20:16:48 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id C5AB568B1F1; Sat, 5 Nov 2022 22:16:40 +0200 (EET) Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 2249868B1CE for ; Sat, 5 Nov 2022 22:16:34 +0200 (EET) Received: (Authenticated sender: michael@niedermayer.cc) by mail.gandi.net (Postfix) with ESMTPSA id 0270C1BF20A for ; Sat, 5 Nov 2022 20:16:32 +0000 (UTC) From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Sat, 5 Nov 2022 21:16:27 +0100 Message-Id: <20221105201629.1980-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20221105201629.1980-1-michael@niedermayer.cc> References: <20221105201629.1980-1-michael@niedermayer.cc> Subject: [FFmpeg-devel] [PATCH 2/4] avcodec/bonk: decode multiple passes in intlist_read() at once X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: This makes the worst case much faster Fixes: Timeout Fixes: 51363/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-5660734784143360 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/bonk.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/libavcodec/bonk.c b/libavcodec/bonk.c index 409694f710..471e09fe14 100644 --- a/libavcodec/bonk.c +++ b/libavcodec/bonk.c @@ -159,6 +159,7 @@ static int intlist_read(BonkContext *s, int *buf, int entries, int base_2_part) int n_zeros = 0, step = 256, dominant = 0; int pos = 0, level = 0; BitCount *bits = s->bits; + int passes = 1; memset(buf, 0, entries * sizeof(*buf)); if (base_2_part) { @@ -222,21 +223,25 @@ static int intlist_read(BonkContext *s, int *buf, int entries, int base_2_part) x = 0; n_zeros = 0; for (i = 0; n_zeros < entries; i++) { + if (x >= max_x) + return AVERROR_INVALIDDATA; + if (pos >= entries) { pos = 0; - level += 1 << low_bits; + level += passes << low_bits; + passes = 1; + if (bits[x].bit && bits[x].count > entries - n_zeros) + passes = bits[x].count / (entries - n_zeros); } - if (x >= max_x) - return AVERROR_INVALIDDATA; - if (buf[pos] >= level) { if (bits[x].bit) - buf[pos] += 1 << low_bits; + buf[pos] += passes << low_bits; else n_zeros++; - bits[x].count--; + av_assert1(bits[x].count >= passes); + bits[x].count -= passes; x += bits[x].count == 0; } -- 2.17.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".