From 19ad05e9e0f045b13de8de7300ca3bd34ea8ca53 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 20 Mar 2024 03:27:13 +0100 Subject: [PATCH] avcodec/jpeg2000htdec: Check magp before using it in a shift Fixes: shift exponent -1 is negative Fixes: 65378/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-5457678193197056 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/jpeg2000dec.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index 857379da2d..28bf6be2fe 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -1886,7 +1886,7 @@ static inline void roi_scale_cblk(Jpeg2000Cblk *cblk, } } -static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile *tile) +static inline int tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile *tile) { Jpeg2000T1Context t1; @@ -1911,6 +1911,8 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile int nb_precincts, precno; Jpeg2000Band *band = rlevel->band + bandno; int cblkno = 0, bandpos; + /* See Rec. ITU-T T.800, Equation E-2 */ + int magp = quantsty->expn[subbandno] + quantsty->nguardbits - 1; bandpos = bandno + (reslevelno > 0); @@ -1918,6 +1920,11 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile band->coord[1][0] == band->coord[1][1]) continue; + if ((codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F) && magp >= 31) { + avpriv_request_sample(s->avctx, "JPEG2000_CTSY_HTJ2K_F and magp >= 31"); + return AVERROR_PATCHWELCOME; + } + nb_precincts = rlevel->num_precincts_x * rlevel->num_precincts_y; /* Loop on precincts */ for (precno = 0; precno < nb_precincts; precno++) { @@ -1928,8 +1935,6 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile cblkno < prec->nb_codeblocks_width * prec->nb_codeblocks_height; cblkno++) { int x, y, ret; - /* See Rec. ITU-T T.800, Equation E-2 */ - int magp = quantsty->expn[subbandno] + quantsty->nguardbits - 1; Jpeg2000Cblk *cblk = prec->cblk + cblkno; @@ -1969,6 +1974,7 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile ff_dwt_decode(&comp->dwt, codsty->transform == FF_DWT97 ? (void*)comp->f_data : (void*)comp->i_data); } /*end comp */ + return 0; } #define WRITE_FRAME(D, PIXEL) \ @@ -2045,7 +2051,9 @@ static int jpeg2000_decode_tile(AVCodecContext *avctx, void *td, AVFrame *picture = td; Jpeg2000Tile *tile = s->tile + jobnr; - tile_codeblocks(s, tile); + int ret = tile_codeblocks(s, tile); + if (ret < 0) + return ret; /* inverse MCT transformation */ if (tile->codsty[0].mct)