From owner-svn-src-all@freebsd.org Sat Mar 14 14:04:56 2020 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3C24C25A47F; Sat, 14 Mar 2020 14:04:56 +0000 (UTC) (envelope-from bz@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 48fkpc0l2kz4GQ9; Sat, 14 Mar 2020 14:04:56 +0000 (UTC) (envelope-from bz@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 103001FF91; Sat, 14 Mar 2020 14:04:56 +0000 (UTC) (envelope-from bz@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 02EE4tgv089111; Sat, 14 Mar 2020 14:04:55 GMT (envelope-from bz@FreeBSD.org) Received: (from bz@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 02EE4tXg089110; Sat, 14 Mar 2020 14:04:55 GMT (envelope-from bz@FreeBSD.org) Message-Id: <202003141404.02EE4tXg089110@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: bz set sender to bz@FreeBSD.org using -f From: "Bjoern A. Zeeb" Date: Sat, 14 Mar 2020 14:04:55 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r358992 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: bz X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 358992 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 Mar 2020 14:04:56 -0000 Author: bz Date: Sat Mar 14 14:04:55 2020 New Revision: 358992 URL: https://svnweb.freebsd.org/changeset/base/358992 Log: kern_jail: missing \0 termination check on osrelease parameter If a user spplies a non-\0 terminated osrelease parameter reading it back may disclose kernel memory. This is a problem in case of nested jails (children.max > 0, which is not the default). Otherwise root outside the jail has access to kernel memory by other means and root inside a jail cannot create a child jail. Add the proper \0 check at the end of a supplied osrelease parameter and make sure any copies of the field will be \0-terminated. Submitted by: Hans Christian Woithe (chwoithe yahoo.com) MFC after: 3 days Modified: head/sys/kern/kern_jail.c Modified: head/sys/kern/kern_jail.c ============================================================================== --- head/sys/kern/kern_jail.c Sat Mar 14 11:55:27 2020 (r358991) +++ head/sys/kern/kern_jail.c Sat Mar 14 14:04:55 2020 (r358992) @@ -865,8 +865,12 @@ kern_jail_set(struct thread *td, struct uio *optuio, i "osrelease cannot be changed after creation"); goto done_errmsg; } - if (len == 0 || len >= OSRELEASELEN) { + if (len == 0 || osrelstr[len - 1] != '\0') { error = EINVAL; + goto done_free; + } + if (len >= OSRELEASELEN) { + error = ENAMETOOLONG; vfs_opterror(opts, "osrelease string must be 1-%d bytes long", OSRELEASELEN - 1); @@ -1241,9 +1245,11 @@ kern_jail_set(struct thread *td, struct uio *optuio, i pr->pr_osreldate = osreldt ? osreldt : ppr->pr_osreldate; if (osrelstr == NULL) - strcpy(pr->pr_osrelease, ppr->pr_osrelease); + strlcpy(pr->pr_osrelease, ppr->pr_osrelease, + sizeof(pr->pr_osrelease)); else - strcpy(pr->pr_osrelease, osrelstr); + strlcpy(pr->pr_osrelease, osrelstr, + sizeof(pr->pr_osrelease)); LIST_INIT(&pr->pr_children); mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF | MTX_DUPOK);