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Patch in a candidate fix for ossfuzz issue 24232

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- Improves handling of certain invalid PNGs by stb_image
This commit is contained in:
Benjamin A. Beasley 2022-11-30 18:15:34 -05:00
parent ef095c651c
commit e53fbc0d95
2 changed files with 42 additions and 1 deletions
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32
1230.patch Normal file
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@ -0,0 +1,32 @@
From b5d9d9719b001c67ca922df547a85a0fae364997 Mon Sep 17 00:00:00 2001
From: Neil Bickford <nbickford@nvidia.com>
Date: Fri, 15 Oct 2021 11:04:41 -0700
Subject: [PATCH] stb_image PNG: Checks for invalid DEFLATE codes.
Specifically, this rejects length codes 286 and 287, and distance codes 30 and 31.
This avoids a scenario in which a file could contain a table in which
0 corresponded to length code 287, which would result in writing 0 bits.
Signed-off-by: Neil Bickford <nbickford@nvidia.com>
---
stb_image.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/stb_image.h b/stb_image.h
index d60371b95..ab616c56d 100644
--- a/stb_image.h
+++ b/stb_image.h
@@ -4256,11 +4256,12 @@ static int stbi__parse_huffman_block(stbi__zbuf *a)
a->zout = zout;
return 1;
}
+ if (z >= 286) return stbi__err("bad huffman code","Corrupt PNG"); // per DEFLATE, length codes 286 and 287 must not appear in compressed data
z -= 257;
len = stbi__zlength_base[z];
if (stbi__zlength_extra[z]) len += stbi__zreceive(a, stbi__zlength_extra[z]);
z = stbi__zhuffman_decode(a, &a->z_distance);
- if (z < 0) return stbi__err("bad huffman code","Corrupt PNG");
+ if (z < 0 || z >= 30) return stbi__err("bad huffman code","Corrupt PNG"); // per DEFLATE, distance codes 30 and 31 must not appear in compressed data
dist = stbi__zdist_base[z];
if (stbi__zdist_extra[z]) dist += stbi__zreceive(a, stbi__zdist_extra[z]);
if (zout - a->zout_start < dist) return stbi__err("bad dist","Corrupt PNG");

11
stb.spec
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@ -101,10 +101,19 @@ Patch: %{url}/pull/1236.patch
#
# ----
#
# Additional stb_image fixes for bugs from ossfuzz and issues 1289, 1291, 1292, and 1293
# Additional stb_image fixes for bugs from ossfuzz and issues 1289, 1291, 1292,
# and 1293
# https://github.com/nothings/stb/pull/1297
Patch: %{url}/pull/1297.patch
# stb_image PNG reader: Adds checks for invalid DEFLATE codes, fixing an
# infinite loop found by ossfuzz.
# https://github.com/nothings/stb/pull/1230
# Fixes:
# Issue 24232: stb:stb_png_read_fuzzer: Timeout in stb_png_read_fuzzer
# https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=24232&q=proj%3Dstb
Patch: %{url}/pull/1230.patch
%global stb_c_lexer_version 0.12
%global stb_connected_components_version 0.96
%global stb_divide_version 0.94