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Fix/exif offset hardening #477

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Merged
DichenZhang1 merged 3 commits into from
Sep 18, 2026
Merged

Fix/exif offset hardening #477

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43dd024
jpegr: locate EXIF offsets in source JPEG stream
DichenZhang1 Sep 18, 2026
d36cc98
jpegdecoderhelper: use uint8_t marker code and guard against long ove…
DichenZhang1 Sep 18, 2026
4f31f40
Merge branch 'main' into fix/exif-offset-hardening
DichenZhang1 Sep 18, 2026
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6 changes: 5 additions & 1 deletion lib/src/jpegdecoderhelper.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@

#include <cmath>
#include <cstring>
#include <limits>

#include "ultrahdr/ultrahdrcommon.h"
#include "ultrahdr/jpegdecoderhelper.h"
Expand Down Expand Up @@ -141,7 +142,7 @@ static void jpeg_extract_marker_payload(const j_decompress_ptr cinfo, const uint

// Locate the selected payload in the original JPEG stream. The saved-marker list is incomplete
// by design and is not a reliable source of byte offsets when other segments precede EXIF.
static long find_marker_payload_offset(const uint8_t* image, size_t length, uint32_t marker_code,
static long find_marker_payload_offset(const uint8_t* image, size_t length, uint8_t marker_code,
const uint8_t* payload, size_t payload_length) {
if (image == nullptr || payload == nullptr || length < 2 || image[0] != 0xff ||
image[1] != 0xd8) {
Expand All @@ -165,6 +166,9 @@ static long find_marker_payload_offset(const uint8_t* image, size_t length, uint
const size_t segment_payload_offset = pos + 2;
if (marker == marker_code && segment_payload_length == payload_length &&
memcmp(image + segment_payload_offset, payload, payload_length) == 0) {
if (segment_payload_offset > static_cast<size_t>(std::numeric_limits<long>::max())) {
return -1;
}
return static_cast<long>(segment_payload_offset);
}
pos += segment_length;
Expand Down
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