ext/ftp: fix out-of-bounds read in ftp_get() ASCII CRLF translation#22328
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ext/ftp: fix out-of-bounds read in ftp_get() ASCII CRLF translation#22328iliaal wants to merge 1 commit into
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In ASCII mode ftp_get() scans each received block for '\r' and peeks at the next byte to collapse a CRLF pair to '\n'. When the '\r' is the last byte of a full FTP_BUFSIZE block, the *(s + 1) lookahead reads one byte past the data buffer; a server placing '\r' at offset 4095 of a 4096-byte read triggers it. Bound the lookahead to the received data, matching the guard ftp_readline() already uses. ftp_nb_continue_read() carries the trailing '\r' across reads via ftp->lastch and is unaffected. Closes phpGH-22328
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In ASCII mode ftp_get() peeks at the byte after each '\r' to fold CRLF into LF. When that '\r' is the last byte of a full FTP_BUFSIZE read, the lookahead reads one byte past the buffer; a server placing '\r' at offset 4095 of a 4096-byte read hits it (ASAN: heap-buffer-overflow read of size 1). Bound the lookahead to the received data, as ftp_readline() does. ftp_nb_continue_read() carries the trailing '\r' across reads and isn't affected.