|
| 1 | +From 8a9dbada543f4241da70c00c353d1aa0e133b6a2 Mon Sep 17 00:00:00 2001 |
| 2 | +From: Henrik Gramner <gramner@twoorioles.com> |
| 3 | +Date: Tue, 21 Nov 2023 20:47:50 +0100 |
| 4 | +Subject: [PATCH] Fix tile_start_off calculations for extremely large frame |
| 5 | + sizes |
| 6 | + |
| 7 | +The tile start offset, in pixels, can exceed the range of a signed int. |
| 8 | + |
| 9 | +CVE: CVE-2024-1580 |
| 10 | +Upstream-Status: Backport [https://code.videolan.org/videolan/dav1d/-/commit/2b475307dc11be9a1c3cc4358102c76a7f386a51] |
| 11 | +--- |
| 12 | + src/decode.c | 13 +++++++------ |
| 13 | + src/internal.h | 2 +- |
| 14 | + 2 files changed, 8 insertions(+), 7 deletions(-) |
| 15 | + |
| 16 | +diff --git a/src/decode.c b/src/decode.c |
| 17 | +index d810ed2..f1aa6ce 100644 |
| 18 | +--- a/src/decode.c |
| 19 | ++++ b/src/decode.c |
| 20 | +@@ -2359,7 +2359,7 @@ static void setup_tile(Dav1dTileState *const ts, |
| 21 | + const Dav1dFrameContext *const f, |
| 22 | + const uint8_t *const data, const size_t sz, |
| 23 | + const int tile_row, const int tile_col, |
| 24 | +- const int tile_start_off) |
| 25 | ++ const unsigned tile_start_off) |
| 26 | + { |
| 27 | + const int col_sb_start = f->frame_hdr->tiling.col_start_sb[tile_col]; |
| 28 | + const int col_sb128_start = col_sb_start >> !f->seq_hdr->sb128; |
| 29 | +@@ -2758,15 +2758,16 @@ int dav1d_decode_frame(Dav1dFrameContext *const f) { |
| 30 | + const uint8_t *const size_mul = ss_size_mul[f->cur.p.layout]; |
| 31 | + const int hbd = !!f->seq_hdr->hbd; |
| 32 | + if (c->n_fc > 1) { |
| 33 | ++ const unsigned sb_step4 = f->sb_step * 4; |
| 34 | + int tile_idx = 0; |
| 35 | + for (int tile_row = 0; tile_row < f->frame_hdr->tiling.rows; tile_row++) { |
| 36 | +- int row_off = f->frame_hdr->tiling.row_start_sb[tile_row] * |
| 37 | +- f->sb_step * 4 * f->sb128w * 128; |
| 38 | +- int b_diff = (f->frame_hdr->tiling.row_start_sb[tile_row + 1] - |
| 39 | +- f->frame_hdr->tiling.row_start_sb[tile_row]) * f->sb_step * 4; |
| 40 | ++ const unsigned row_off = f->frame_hdr->tiling.row_start_sb[tile_row] * |
| 41 | ++ sb_step4 * f->sb128w * 128; |
| 42 | ++ const unsigned b_diff = (f->frame_hdr->tiling.row_start_sb[tile_row + 1] - |
| 43 | ++ f->frame_hdr->tiling.row_start_sb[tile_row]) * sb_step4; |
| 44 | + for (int tile_col = 0; tile_col < f->frame_hdr->tiling.cols; tile_col++) { |
| 45 | + f->frame_thread.tile_start_off[tile_idx++] = row_off + b_diff * |
| 46 | +- f->frame_hdr->tiling.col_start_sb[tile_col] * f->sb_step * 4; |
| 47 | ++ f->frame_hdr->tiling.col_start_sb[tile_col] * sb_step4; |
| 48 | + } |
| 49 | + } |
| 50 | + |
| 51 | +diff --git a/src/internal.h b/src/internal.h |
| 52 | +index fb84422..cdaaa47 100644 |
| 53 | +--- a/src/internal.h |
| 54 | ++++ b/src/internal.h |
| 55 | +@@ -233,7 +233,7 @@ struct Dav1dFrameContext { |
| 56 | + coef *cf; |
| 57 | + int pal_sz, pal_idx_sz, cf_sz; |
| 58 | + // start offsets per tile |
| 59 | +- int *tile_start_off; |
| 60 | ++ unsigned *tile_start_off; |
| 61 | + } frame_thread; |
| 62 | + |
| 63 | + // loopfilter |
| 64 | +-- |
| 65 | +2.34.1 |
| 66 | + |
0 commit comments