From db51f193e4d4c135164656b33adad519cd19b8be Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 12 Sep 2022 19:55:09 +0200 Subject: [PATCH] avcodec/tiff: Fix loop detection Fixes regression with tickets/4364/L1004220.DNG Reviewed-by: Paul B Mahol Signed-off-by: Michael Niedermayer (cherry picked from commit 43a4854510a3d596e114d899177a5b3b323ca9fb) Signed-off-by: Michael Niedermayer --- libavcodec/tiff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c index 34aab924d3..f66268568d 100644 --- a/libavcodec/tiff.c +++ b/libavcodec/tiff.c @@ -1750,7 +1750,7 @@ static int decode_frame(AVCodecContext *avctx, TiffContext *const s = avctx->priv_data; AVFrame *const p = data; ThreadFrame frame = { .f = data }; - unsigned off, last_off; + unsigned off, last_off = 0; int le, ret, plane, planes; int i, j, entries, stride; unsigned soff, ssize; @@ -1815,7 +1815,6 @@ again: /** whether we should process this multi-page IFD's next page */ retry_for_page = s->get_page && s->cur_page + 1 < s->get_page; // get_page is 1-indexed - last_off = off; if (retry_for_page) { // set offset to the next IFD off = ff_tget_long(&s->gb, le); @@ -1833,6 +1832,7 @@ again: avpriv_request_sample(s->avctx, "non increasing IFD offset"); return AVERROR_INVALIDDATA; } + last_off = off; if (off >= UINT_MAX - 14 || avpkt->size < off + 14) { av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n"); return AVERROR_INVALIDDATA;