ext/standard: reject a dechunk chunk size that overflows size_t#22786
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iliaal wants to merge 1 commit into
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ext/standard: reject a dechunk chunk size that overflows size_t#22786iliaal wants to merge 1 commit into
iliaal wants to merge 1 commit into
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php_dechunk() accumulated the hex chunk size with chunk_size * 16 + digit and never checked the multiply, so a size of 2^64 wrapped to 0. A zero size reads as the terminating chunk, so the filter stopped there and dropped the body it had been handed. Error out instead, as the other malformed-size cases already do.
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php_dechunk()accumulated the hex chunk size withchunk_size * 16 + digitand never checked the multiply. A size of10000000000000000is 2^64, which wraps to 0, and 0 reads as the terminating chunk, so the filter stops and drops the body it was handed:The guard is hoisted out of the three digit branches rather than repeated in each, which needs the digit value computed first.
SIZE_MAX / 16is sufficient for the add as well: the largest value that survives it isSIZE_MAX / 16, andSIZE_MAX / 16 * 16 + 15is exactlySIZE_MAX.