PR #23628 opened by michaelni URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23628 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23628.patch
Found-by: bikini (github.com/bikini/exploitarium) Fixes: out of array access Fixes: rowspill_128x1.avi / gen_rowspill_avi.py Fixes: xGV79bIb7uAJ >From 7ae64dba3c5ee27e63efe5958d20d96f6f03da9b Mon Sep 17 00:00:00 2001 From: Umar Pathan <[email protected]> Date: Sun, 28 Jun 2026 23:02:52 +0200 Subject: [PATCH] avcodec/rasc: Check that 32-bit DLTA accesses stay within the row Found-by: bikini (github.com/bikini/exploitarium) Fixes: out of array access Fixes: rowspill_128x1.avi / gen_rowspill_avi.py Fixes: xGV79bIb7uAJ --- libavcodec/rasc.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/libavcodec/rasc.c b/libavcodec/rasc.c index 5f956a9b2c..d784a44063 100644 --- a/libavcodec/rasc.c +++ b/libavcodec/rasc.c @@ -320,6 +320,11 @@ static int decode_move(AVCodecContext *avctx, return 0; } +static inline int dlta_room(unsigned cx, unsigned w, unsigned bpp, unsigned need) +{ + return cx + need <= w * bpp; +} + #define NEXT_LINE \ if (cx >= w * s->bpp) { \ cx = 0; \ @@ -418,6 +423,8 @@ static int decode_dlta(AVCodecContext *avctx, case 4: fill = bytestream2_get_byte(&dc); while (len > 0 && cy > 0) { + if (!dlta_room(cx, w, s->bpp, 4)) + return AVERROR_INVALIDDATA; AV_WL32(b1 + cx, AV_RL32(b2 + cx)); AV_WL32(b2 + cx, fill); cx++; @@ -427,6 +434,8 @@ static int decode_dlta(AVCodecContext *avctx, case 7: fill = bytestream2_get_le32(&dc); while (len > 0 && cy > 0) { + if (!dlta_room(cx, w, s->bpp, 4)) + return AVERROR_INVALIDDATA; AV_WL32(b1 + cx, AV_RL32(b2 + cx)); AV_WL32(b2 + cx, fill); cx += 4; @@ -443,6 +452,8 @@ static int decode_dlta(AVCodecContext *avctx, while (len > 0 && cy > 0) { unsigned v0, v1; + if (!dlta_room(cx, w, s->bpp, 4)) + return AVERROR_INVALIDDATA; v0 = AV_RL32(b2 + cx); v1 = AV_RL32(b1 + cx); AV_WL32(b2 + cx, v1); @@ -454,6 +465,8 @@ static int decode_dlta(AVCodecContext *avctx, case 13: while (len > 0 && cy > 0) { fill = bytestream2_get_le32(&dc); + if (!dlta_room(cx, w, s->bpp, 4)) + return AVERROR_INVALIDDATA; AV_WL32(b1 + cx, AV_RL32(b2 + cx)); AV_WL32(b2 + cx, fill); cx += 4; -- 2.52.0 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
