fix(bmp): bomb guard, UB-safe height negation, and scanline bounds - #5371
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fix(bmp): bomb guard, UB-safe height negation, and scanline bounds#5371lgritz wants to merge 1 commit into
lgritz wants to merge 1 commit into
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Harden the BMP reader: - check_compression_ratio() rejects a tiny file with implausibly high resolutions according to the header. - Negate the height field in 64-bit. -m_dib_header.height is signed- overflow UB when the attacker-controlled int32 height is INT32_MIN; check_open() then rejects the out-of-range value cleanly. - read_native_scanline() rejected y > height, allowing y == height. Should have been `>=` all along. Assisted-by: Claude Code / Claude Opus 4.8 Signed-off-by: Larry Gritz <lg@larrygritz.com>
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Harden the BMP reader:
-m_dib_header.heightis signed, it could lead to overflow UB when the attacker-controlled int32 height is INT32_MIN; check_open() then rejects the out-of-range value cleanly.>=all along.Assisted-by: Claude Code / Claude Opus 4.8