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 B487444DC7 for ; Tue, 22 Nov 2022 22:57:09 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id A2FD568BB9A; Wed, 23 Nov 2022 00:57:01 +0200 (EET) Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 516CC68B9FF for ; Wed, 23 Nov 2022 00:56:55 +0200 (EET) Received: (Authenticated sender: michael@niedermayer.cc) by mail.gandi.net (Postfix) with ESMTPSA id 6E0D2E0003 for ; Tue, 22 Nov 2022 22:56:54 +0000 (UTC) From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Tue, 22 Nov 2022 23:56:52 +0100 Message-Id: <20221122225652.1341-2-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20221122225652.1341-1-michael@niedermayer.cc> References: <20221122225652.1341-1-michael@niedermayer.cc> Subject: [FFmpeg-devel] [PATCH 2/2] avcodec/ffv1dec: restructure slice coordinate reading a bit 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: Fixes: signed integer overflow: -1094995528 * 8224 cannot be represented in type 'int' Fixes: 53508/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFV1_fuzzer-474551033462784 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/ffv1dec.c | 63 +++++++++++++++++++++++++------------------- 1 file changed, 36 insertions(+), 27 deletions(-) diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c index b1cfc4bf57..e489030d3b 100644 --- a/libavcodec/ffv1dec.c +++ b/libavcodec/ffv1dec.c @@ -169,23 +169,28 @@ static int decode_slice_header(const FFV1Context *f, FFV1Context *fs) uint8_t state[CONTEXT_SIZE]; unsigned ps, i, context_count; memset(state, 128, sizeof(state)); + int sx = get_symbol(c, state, 0); + int sy = get_symbol(c, state, 0); + int sw = get_symbol(c, state, 0) + 1U; + int sh = get_symbol(c, state, 0) + 1U; av_assert0(f->version > 2); - fs->slice_x = get_symbol(c, state, 0) * f->width ; - fs->slice_y = get_symbol(c, state, 0) * f->height; - fs->slice_width = (get_symbol(c, state, 0) + 1) * f->width + fs->slice_x; - fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y; - - fs->slice_x /= f->num_h_slices; - fs->slice_y /= f->num_v_slices; - fs->slice_width = fs->slice_width /f->num_h_slices - fs->slice_x; - fs->slice_height = fs->slice_height/f->num_v_slices - fs->slice_y; - if ((unsigned)fs->slice_width > f->width || (unsigned)fs->slice_height > f->height) - return -1; - if ( (unsigned)fs->slice_x + (uint64_t)fs->slice_width > f->width - || (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height) - return -1; + + if (sx < 0 || sy < 0 || sw <= 0 || sh <= 0) + return AVERROR_INVALIDDATA; + if (sx > f->num_h_slices - sw || sy > f->num_v_slices - sh) + return AVERROR_INVALIDDATA; + + fs->slice_x = sx * (int64_t)f->width / f->num_h_slices; + fs->slice_y = sy * (int64_t)f->height / f->num_v_slices; + fs->slice_width = (sx + sw) * (int64_t)f->width / f->num_h_slices - fs->slice_x; + fs->slice_height = (sy + sh) * (int64_t)f->height / f->num_v_slices - fs->slice_y; + + av_assert0((unsigned)fs->slice_width <= f->width && + (unsigned)fs->slice_height <= f->height); + av_assert0 ( (unsigned)fs->slice_x + (uint64_t)fs->slice_width <= f->width + && (unsigned)fs->slice_y + (uint64_t)fs->slice_height <= f->height); if (fs->ac == AC_GOLOMB_RICE && fs->slice_width >= (1<<23)) return AVERROR_INVALIDDATA; @@ -770,21 +775,25 @@ static int read_header(FFV1Context *f) fs->slice_damaged = 0; if (f->version == 2) { - fs->slice_x = get_symbol(c, state, 0) * f->width ; - fs->slice_y = get_symbol(c, state, 0) * f->height; - fs->slice_width = (get_symbol(c, state, 0) + 1) * f->width + fs->slice_x; - fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y; - - fs->slice_x /= f->num_h_slices; - fs->slice_y /= f->num_v_slices; - fs->slice_width = fs->slice_width / f->num_h_slices - fs->slice_x; - fs->slice_height = fs->slice_height / f->num_v_slices - fs->slice_y; - if ((unsigned)fs->slice_width > f->width || - (unsigned)fs->slice_height > f->height) + int sx = get_symbol(c, state, 0); + int sy = get_symbol(c, state, 0); + int sw = get_symbol(c, state, 0) + 1U; + int sh = get_symbol(c, state, 0) + 1U; + + if (sx < 0 || sy < 0 || sw <= 0 || sh <= 0) return AVERROR_INVALIDDATA; - if ( (unsigned)fs->slice_x + (uint64_t)fs->slice_width > f->width - || (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height) + if (sx > f->num_h_slices - sw || sy > f->num_v_slices - sh) return AVERROR_INVALIDDATA; + + fs->slice_x = sx * (int64_t)f->width / f->num_h_slices; + fs->slice_y = sy * (int64_t)f->height / f->num_v_slices; + fs->slice_width = (sx + sw) * (int64_t)f->width / f->num_h_slices - fs->slice_x; + fs->slice_height = (sy + sh) * (int64_t)f->height / f->num_v_slices - fs->slice_y; + + av_assert0((unsigned)fs->slice_width <= f->width && + (unsigned)fs->slice_height <= f->height); + av_assert0 ( (unsigned)fs->slice_x + (uint64_t)fs->slice_width <= f->width + && (unsigned)fs->slice_y + (uint64_t)fs->slice_height <= f->height); } for (i = 0; i < f->plane_count; i++) { -- 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".