From owner-freebsd-bugs@FreeBSD.ORG Wed Dec 29 23:20:31 2004 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 64B1516A4CE for ; Wed, 29 Dec 2004 23:20:31 +0000 (GMT) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4E6D143D3F for ; Wed, 29 Dec 2004 23:20:31 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.1/8.13.1) with ESMTP id iBTNKV5C027016 for ; Wed, 29 Dec 2004 23:20:31 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.1/8.13.1/Submit) id iBTNKVRe027015; Wed, 29 Dec 2004 23:20:31 GMT (envelope-from gnats) Date: Wed, 29 Dec 2004 23:20:31 GMT Message-Id: <200412292320.iBTNKVRe027015@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Przemyslaw Frasunek Subject: Re: bin/75638: sscanf %lld broken on 4.x X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Przemyslaw Frasunek List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Dec 2004 23:20:31 -0000 The following reply was made to PR bin/75638; it has been noted by GNATS. From: Przemyslaw Frasunek To: freebsd-gnats-submit@FreeBSD.org Cc: Subject: Re: bin/75638: sscanf %lld broken on 4.x Date: Thu, 30 Dec 2004 00:16:34 +0100 > sscanf(s, "%lld", &l) will not set l to valid value if l was previously > not zero. well, not exactly non-zero. the problem occurs when l if initialized with value greater than 0xffffffff: lagoon:venglin:~> cat test.c #include int main(void) { //long long value = 0x100000000L; long long value = 0xffffffff; char *s = "10"; fprintf(stderr, "%lld %s\n", value, s); sscanf(s, "%lld", &value); fprintf(stderr, "%lld %s\n", value, s); } lagoon:venglin:~> cc -o test test.c lagoon:venglin:~> ./test 4294967295 10 10 10 lagoon:venglin:~> cat test.c #include int main(void) { long long value = 0x100000000L; //long long value = 0xffffffff; char *s = "10"; fprintf(stderr, "%lld %s\n", value, s); sscanf(s, "%lld", &value); fprintf(stderr, "%lld %s\n", value, s); } lagoon:venglin:~> cc -o test test.c lagoon:venglin:~> ./test 4294967296 10 4294967306 10 it looks like classical unsigned integer overflow, which could have some yet unknown security implications. -- * Fido: 2:480/124 ** WWW: http://www.frasunek.com/ ** NICHDL: PMF9-RIPE * * JID: venglin@jabber.atman.pl ** PGP ID: 2578FCAD ** HAM-RADIO: SQ8JIV *