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| author | Lei Zhang <thestig@chromium.org> | 2018-10-01 17:47:52 +0000 |
|---|---|---|
| committer | Lei Zhang <thestig@chromium.org> | 2018-10-01 17:47:52 +0000 |
| commit | 13b08aa11de74120909b871b987d010f33cd0bc6 (patch) | |
| tree | df5c1ce27d6beae6f6ad544e73cc5b318c8a8137 | |
| parent | 0004bd334b0c485b2e4ece0bfae8812c7f107a0d (diff) | |
| download | pdfium-13b08aa11de74120909b871b987d010f33cd0bc6.tar.xz | |
M70: Avoid CHECK in fpdf_parser_decode.cpp (memcpy empty span)chromium/3538
Given a span of size N, memcpy(dest, &span[N], 0) ought to be a no-op,
but since we compute span[N] before checking for zero length, we hit
an assert. The correct idiom should be to create a sub-span, which
allows specifying N, but only when the size is 0.
Bug: chromium:879910,chromium:889356
Change-Id: Ic6f368109a5c2f1e13a5f638c6a233769e2ad41b
Reviewed-on: https://pdfium-review.googlesource.com/41930
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
(cherry picked from commit 73e97f4fac2f4f591ff62e70377a80fd40b5f6f3)
Reviewed-on: https://pdfium-review.googlesource.com/43271
| -rw-r--r-- | core/fpdfapi/parser/fpdf_parser_decode.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.cpp b/core/fpdfapi/parser/fpdf_parser_decode.cpp index 7a9f798c85..e8bb21ca92 100644 --- a/core/fpdfapi/parser/fpdf_parser_decode.cpp +++ b/core/fpdfapi/parser/fpdf_parser_decode.cpp @@ -256,7 +256,8 @@ uint32_t RunLengthDecode(pdfium::span<const uint8_t> src_span, copy_len = buf_left; memset(*dest_buf + dest_count + copy_len, '\0', delta); } - memcpy(*dest_buf + dest_count, &src_span[i + 1], copy_len); + auto copy_span = src_span.subspan(i + 1, copy_len); + memcpy(*dest_buf + dest_count, copy_span.data(), copy_span.size()); dest_count += src_span[i] + 1; i += src_span[i] + 2; } else { |