fix: bounds-check nul sentinel in struct key escape scan (checkptr OOB) - #590
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momomuchu wants to merge 1 commit into
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fix: bounds-check nul sentinel in struct key escape scan (checkptr OOB)#590momomuchu wants to merge 1 commit into
momomuchu wants to merge 1 commit into
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decodeKeyCharByEscapedChar did not handle a dangling backslash at the end of the buffer. It treated the trailing nul sentinel as an unrecognized escaped char and returned a cursor past it, letting decodeKeyByBitmapUint8's raw char() read walk one byte past the allocation. Fatal under checkptr/-race on malformed input. Fixes goccy#577, goccy#575
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Fixes #577 (also fixes the #575 duplicate).
decodeKeyByBitmapUint8scans struct keys with raw unsafe.Pointerarithmetic via
char(). On a dangling backslash at the end of thebuffer (e.g.
{"hAs\),decodeKeyCharByEscapedCharhad no case for thetrailing nul sentinel, so it fell through to the unmatched-case
return nil, cursor, niland handed back a cursor still pointing atthe sentinel. The caller then advances one past it, and the next
char()reads one byte past the backing allocation. Under-race(which enables checkptr) that is a fatal, unrecoverable crash instead
of a decode error.
Handle nul as end of input and return
ErrUnexpectedEndOfJSON, thesame error the surrounding key decoder already returns for other
truncated-input cases. Confirmed the checkptr crash on master before
the change and its absence after, under
go test -race.Added TestIssue577 with the reported repro plus a few more
dangling-backslash variants, in the style of TestIssue429.