Curl_dedotdotify(): always nul terminate returned string. #3039
This fixes potential out-of-buffer access on "file:./" URL
$ valgrind curl "file:./"
Was originally spotted by
This fixes potential out-of-buffer access on "file:./" URL $ valgrind curl "file:./" ==24516== Memcheck, a memory error detector ==24516== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al. ==24516== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info ==24516== Command: /home/even/install-curl-git/bin/curl file:./ ==24516== ==24516== Conditional jump or move depends on uninitialised value(s) ==24516== at 0x4C31F9C: strcmp (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==24516== by 0x4EBB315: seturl (urlapi.c:801) ==24516== by 0x4EBB568: parseurl (urlapi.c:861) ==24516== by 0x4EBC509: curl_url_set (urlapi.c:1199) ==24516== by 0x4E644C6: parseurlandfillconn (url.c:2044) ==24516== by 0x4E67AEF: create_conn (url.c:3613) ==24516== by 0x4E68A4F: Curl_connect (url.c:4119) ==24516== by 0x4E7F0A4: multi_runsingle (multi.c:1440) ==24516== by 0x4E808E5: curl_multi_perform (multi.c:2173) ==24516== by 0x4E7558C: easy_transfer (easy.c:686) ==24516== by 0x4E75801: easy_perform (easy.c:779) ==24516== by 0x4E75868: curl_easy_perform (easy.c:798) Was originally spotted by https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=10637 Credit to OSS-Fuzz