From owner-freebsd-bugs@freebsd.org Tue Mar 1 21:11:42 2016 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 774B0ABF90B for ; Tue, 1 Mar 2016 21:11:42 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4F73D1846 for ; Tue, 1 Mar 2016 21:11:42 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u21LBgu7094307 for ; Tue, 1 Mar 2016 21:11:42 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 207627] Negative array index in ctl.c Date: Tue, 01 Mar 2016 21:11:42 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: cturt@hardenedbsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Mar 2016 21:11:42 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D207627 Bug ID: 207627 Summary: Negative array index in ctl.c Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: cturt@hardenedbsd.org `struct ctl_be_arg` from `sys/cam/ctl/ctl_ioctl.h` declares its sizes as `signed` integers: struct ctl_be_arg { int namelen; char *name; int flags; int vallen; void *value; char *kname; void *kvalue; }; `ctl_copyin_args` from `sys/cam/ctl/ctl.c` copies these values directly from userland with no bound checks, and then goes on to use them in array indexe= s: static struct ctl_be_arg * ctl_copyin_args(int num_args, struct ctl_be_arg *uargs, char *error_str, size_t error_str_len) { struct ctl_be_arg *args; int i; args =3D ctl_copyin_alloc(uargs, num_args * sizeof(*args), error_str, error_str_len); ... for (i =3D 0; i < num_args; i++) { uint8_t *tmpptr; args[i].kname =3D ctl_copyin_alloc(args[i].name, args[i].namelen, error_str, error_str_len); ... if (args[i].kname[args[i].namelen - 1] !=3D '\0') { ... if (args[i].flags & CTL_BEARG_RD) { ... && (tmpptr[args[i].vallen - 1] !=3D '\0')) { For example, if a `args[i].namelen` of 0 is supplied, a read will be perfor= med from `args[i].kname[-1]`. Similarly for `tmpptr` and `vallen`. This range could be extended by supplying negative lengths, however this wo= uld be less likely to be triggerable since the size is converted to `unsigned` = for the allocation and so an allocation of at least 4GB would need to succeed first. --=20 You are receiving this mail because: You are the assignee for the bug.=