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authorLei Zhang <thestig@chromium.org>2018-09-21 15:34:45 +0000
committerChromium commit bot <commit-bot@chromium.org>2018-09-21 15:34:45 +0000
commit8590a98297c5a56e63efc63931c1b3998160e049 (patch)
tree351a3765f746d10a0eb2c6f880864b1603a01e97 /core/fpdfapi
parent9d784c291714b703b16185e69860a3797de85b6c (diff)
downloadpdfium-8590a98297c5a56e63efc63931c1b3998160e049.tar.xz
Validate more image values in CPDF_DIBBase.
Change-Id: Ia5f72e6397ee959d897a945c4069f47c494b5511 Reviewed-on: https://pdfium-review.googlesource.com/42870 Commit-Queue: Ryan Harrison <rharrison@chromium.org> Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Diffstat (limited to 'core/fpdfapi')
-rw-r--r--core/fpdfapi/page/cpdf_image.cpp10
-rw-r--r--core/fpdfapi/page/cpdf_image.h3
-rw-r--r--core/fpdfapi/render/cpdf_dibbase.cpp30
3 files changed, 32 insertions, 11 deletions
diff --git a/core/fpdfapi/page/cpdf_image.cpp b/core/fpdfapi/page/cpdf_image.cpp
index 85e7d8a038..f7eec131ad 100644
--- a/core/fpdfapi/page/cpdf_image.cpp
+++ b/core/fpdfapi/page/cpdf_image.cpp
@@ -32,18 +32,16 @@
#include "third_party/base/numerics/safe_conversions.h"
#include "third_party/base/ptr_util.h"
-namespace {
-
-bool IsValidJpegComponent(int32_t comps) {
+// static
+bool CPDF_Image::IsValidJpegComponent(int32_t comps) {
return comps == 1 || comps == 3 || comps == 4;
}
-bool IsValidJpegBitsPerComponent(int32_t bpc) {
+// static
+bool CPDF_Image::IsValidJpegBitsPerComponent(int32_t bpc) {
return bpc == 1 || bpc == 2 || bpc == 4 || bpc == 8 || bpc == 16;
}
-} // namespace
-
CPDF_Image::CPDF_Image(CPDF_Document* pDoc) : m_pDocument(pDoc) {}
CPDF_Image::CPDF_Image(CPDF_Document* pDoc,
diff --git a/core/fpdfapi/page/cpdf_image.h b/core/fpdfapi/page/cpdf_image.h
index f7752213f1..b4636711fd 100644
--- a/core/fpdfapi/page/cpdf_image.h
+++ b/core/fpdfapi/page/cpdf_image.h
@@ -28,6 +28,9 @@ class CPDF_Image final : public Retainable {
template <typename T, typename... Args>
friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
+ static bool IsValidJpegComponent(int32_t comps);
+ static bool IsValidJpegBitsPerComponent(int32_t bpc);
+
void ConvertStreamToIndirectObject();
CPDF_Dictionary* GetDict() const;
diff --git a/core/fpdfapi/render/cpdf_dibbase.cpp b/core/fpdfapi/render/cpdf_dibbase.cpp
index d342a99ae0..3557672e81 100644
--- a/core/fpdfapi/render/cpdf_dibbase.cpp
+++ b/core/fpdfapi/render/cpdf_dibbase.cpp
@@ -54,7 +54,12 @@ bool GetBitValue(const uint8_t* pSrc, uint32_t pos) {
return pSrc[pos / 8] & (1 << (7 - pos % 8));
}
-bool IsAllowedBPCValue(int bpc) {
+// Just to sanity check and filter out obvious bad values.
+bool IsMaybeValidBitsPerComponent(int bpc) {
+ return bpc >= 0 && bpc <= 16;
+}
+
+bool IsAllowedBitsPerComponent(int bpc) {
return bpc == 1 || bpc == 2 || bpc == 4 || bpc == 8 || bpc == 16;
}
@@ -338,6 +343,9 @@ CPDF_DIBBase::LoadState CPDF_DIBBase::ContinueLoadDIBBase(
bool CPDF_DIBBase::LoadColorInfo(const CPDF_Dictionary* pFormResources,
const CPDF_Dictionary* pPageResources) {
m_bpc_orig = m_pDict->GetIntegerFor("BitsPerComponent");
+ if (!IsMaybeValidBitsPerComponent(m_bpc_orig))
+ return false;
+
if (m_pDict->GetIntegerFor("ImageMask"))
m_bImageMask = true;
@@ -517,6 +525,10 @@ bool CPDF_DIBBase::CreateDCTDecoder(pdfium::span<const uint8_t> src_span,
&bTransform)) {
return false;
}
+ if (!CPDF_Image::IsValidJpegComponent(comps) ||
+ !CPDF_Image::IsValidJpegBitsPerComponent(bpc)) {
+ return false;
+ }
if (m_nComponents == static_cast<uint32_t>(comps)) {
m_bpc = bpc;
@@ -719,10 +731,18 @@ void CPDF_DIBBase::LoadPalette() {
if (!m_pColorSpace || m_Family == PDFCS_PATTERN)
return;
- if (m_bpc == 0 || m_bpc * m_nComponents > 8)
+ if (m_bpc == 0)
return;
- if (m_bpc * m_nComponents == 1) {
+ // Use FX_SAFE_UINT32 just to be on the safe side, in case |m_bpc| or
+ // |m_nComponents| somehow gets a bad value.
+ FX_SAFE_UINT32 safe_bits = m_bpc;
+ safe_bits *= m_nComponents;
+ uint32_t bits = safe_bits.ValueOrDefault(255);
+ if (bits > 8)
+ return;
+
+ if (bits == 1) {
if (m_bDefaultDecode &&
(m_Family == PDFCS_DEVICEGRAY || m_Family == PDFCS_DEVICERGB)) {
return;
@@ -759,7 +779,7 @@ void CPDF_DIBBase::LoadPalette() {
return;
}
- int palette_count = 1 << (m_bpc * m_nComponents);
+ int palette_count = 1 << bits;
// Using at least 16 elements due to the call m_pColorSpace->GetRGB().
std::vector<float> color_values(std::max(m_nComponents, 16u));
for (int i = 0; i < palette_count; i++) {
@@ -817,7 +837,7 @@ void CPDF_DIBBase::ValidateDictParam() {
}
}
- if (!IsAllowedBPCValue(m_bpc))
+ if (!IsAllowedBitsPerComponent(m_bpc))
m_bpc = 0;
}