fix(iff): reject implausible image dimensions before allocating tile buffer#5284
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lgritz wants to merge 1 commit into
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fix(iff): reject implausible image dimensions before allocating tile buffer#5284lgritz wants to merge 1 commit into
lgritz wants to merge 1 commit into
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…buffer TBHD width/height/channel fields were never cross-checked against how much tile data the file actually contains, so a corrupt header could claim an arbitrarily large image (e.g. 16k x 16k) backed by only a few hundred bytes of real data. readimg() would then resize() a multi-gigabyte buffer for a tiny malformed file, hanging (or very slowly succeeding) instead of failing -- a resource-exhaustion DoS on untrusted input, found via fuzzing. Bound the claimed image size against how much tile data remains in the file, generously allowing for RLE's worst-case 128x expansion ratio, and fail fast if it's implausible. Assisted-by: Claude Code / claude-sonnet-5 Signed-off-by: Larry Gritz <lg@larrygritz.com>
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TBHD width/height/channel fields were never cross-checked against how much tile data the file actually contains, so a corrupt header could claim an arbitrarily large image (e.g. 16k x 16k) backed by only a few hundred bytes of real data. readimg() would then resize() a multi-gigabyte buffer for a tiny malformed file, hanging (or very slowly succeeding) instead of failing -- a resource-exhaustion DoS on untrusted input, found via fuzzing.
Bound the claimed image size against how much tile data remains in the file, generously allowing for RLE's worst-case 128x expansion ratio, and fail fast if it's implausible.
Assisted-by: Claude Code / claude-sonnet-5