Move jpeg header read error handling up a level

This move the setjmp needed for handling fatal errors in the jpeg
library up a level to be in line with how other instances of this are
being modified. This additionally reduces the number of times that
setjmp needs to be called and documents why it is occuring.

BUG=pdfium:986

Change-Id: Ia57821e1ce65aae811618effb3f2fa6256e1ab8c
Reviewed-on: https://pdfium-review.googlesource.com/23115
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

2 files changed, 8 insertions, 3 deletions

diff --git a/core/fxcodec/codec/fx_codec_jpeg.cpp b/core/fxcodec/codec/fx_codec_jpeg.cpp
index 4d4adfd817..f7cf291bbf 100644
--- a/core/fxcodec/codec/fx_codec_jpeg.cpp
+++ b/core/fxcodec/codec/fx_codec_jpeg.cpp
@@ -459,9 +459,6 @@ int CCodec_JpegModule::ReadHeader(Context* pContext,
                                   int* nComps) {
 #endif  // PDF_ENABLE_XFA
   auto* ctx = static_cast<CJpegContext*>(pContext);
-  if (setjmp(ctx->m_JumpMark) == -1)
-    return 1;
-
   int ret = jpeg_read_header(&ctx->m_Info, true);
   if (ret == JPEG_SUSPENDED)
     return 2;
diff --git a/core/fxcodec/codec/fx_codec_progress.cpp b/core/fxcodec/codec/fx_codec_progress.cpp
index c9436186ab..c3005bca95 100644
--- a/core/fxcodec/codec/fx_codec_progress.cpp
+++ b/core/fxcodec/codec/fx_codec_progress.cpp
@@ -1105,6 +1105,14 @@ bool CCodec_ProgressiveDecoder::DetectImageType(FXCODEC_IMAGE_TYPE imageType,
       }
       m_offSet += size;
       pJpegModule->Input(m_pJpegContext.get(), m_pSrcBuf, size);
+      // Setting jump marker before calling ReadHeader, since a longjmp to
+      // the marker indicates a fatal error.
+      if (setjmp(*m_pJpegContext->GetJumpMark()) == -1) {
+        m_pJpegContext.reset();
+        m_status = FXCODEC_STATUS_ERR_FORMAT;
+        return false;
+      }
+
       int32_t readResult =
           pJpegModule->ReadHeader(m_pJpegContext.get(), &m_SrcWidth,
                                   &m_SrcHeight, &m_SrcComponents, pAttribute);