fix(dpx): fix heap overflow in 1-channel 10-bit filled scanline swap#5298
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lgritz wants to merge 1 commit into
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fix(dpx): fix heap overflow in 1-channel 10-bit filled scanline swap#5298lgritz wants to merge 1 commit into
lgritz wants to merge 1 commit into
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Read10bitFilled() unpacks a scanline of 10-bit "filled" (Method A/B) samples backwards, and for 1-channel images applies a work-around that swaps the first and third datum of each group of 3 packed samples (so column order comes out right). The swap didn't check that a full group of 3 remained in bounds: whenever the scanline's datum count isn't a multiple of 3, the last (partial) group has only 1 or 2 real datums, and obuf[count + 2] reaches past the end of the caller-owned scanline buffer -- both reading and writing one sample out of bounds. Guard the swap so it only fires when a complete group of 3 remains. Add a regression test in testsuite/dpx using a crafted 1-channel, 10-bit, "Filled method A" DPX subimage (width 80, not a multiple of 3) that reproduces the overflow under ASan prior to this fix. Assisted-by: Claude Code / Sonnet 5 Signed-off-by: Larry Gritz <lg@larrygritz.com>
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Read10bitFilled() unpacks a scanline of 10-bit "filled" (Method A/B) samples backwards, and for 1-channel images applies a workaround that swaps the first and third datum of each group of 3 packed samples (so column order comes out right). The swap didn't check that a full group of 3 remained in bounds. Guard the swap so it only fires when a complete group of 3 remains.
Add a regression test in testsuite/dpx.
Assisted-by: Claude Code / Sonnet 5