From owner-svn-src-all@freebsd.org Wed Jul 3 19:34:19 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E066E15DEC1D; Wed, 3 Jul 2019 19:34:18 +0000 (UTC) (envelope-from kib@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 84EB48CFA0; Wed, 3 Jul 2019 19:34:18 +0000 (UTC) (envelope-from kib@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 55EF818558; Wed, 3 Jul 2019 19:34:18 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x63JYIP7068728; Wed, 3 Jul 2019 19:34:18 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x63JYIRh068727; Wed, 3 Jul 2019 19:34:18 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201907031934.x63JYIRh068727@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Wed, 3 Jul 2019 19:34:18 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r349687 - stable/12/sys/kern X-SVN-Group: stable-12 X-SVN-Commit-Author: kib X-SVN-Commit-Paths: stable/12/sys/kern X-SVN-Commit-Revision: 349687 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 84EB48CFA0 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.97 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.998,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.98)[-0.977,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] 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: Wed, 03 Jul 2019 19:34:19 -0000 Author: kib Date: Wed Jul 3 19:34:17 2019 New Revision: 349687 URL: https://svnweb.freebsd.org/changeset/base/349687 Log: MFC r349320, r349324: coredump: avoid writing to core files not owned by the effective user. PR: 68905 admbugs: 358 Modified: stable/12/sys/kern/kern_sig.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/kern/kern_sig.c ============================================================================== --- stable/12/sys/kern/kern_sig.c Wed Jul 3 19:32:25 2019 (r349686) +++ stable/12/sys/kern/kern_sig.c Wed Jul 3 19:34:17 2019 (r349687) @@ -3400,10 +3400,16 @@ corefile_open_last(struct thread *td, char *name, int } if (oldvp != NULL) { - if (nextvp == NULL) - nextvp = oldvp; - else + if (nextvp == NULL) { + if ((td->td_proc->p_flag & P_SUGID) != 0) { + error = EFAULT; + vnode_close_locked(td, oldvp); + } else { + nextvp = oldvp; + } + } else { vnode_close_locked(td, oldvp); + } } if (error != 0) { if (nextvp != NULL) @@ -3523,6 +3529,8 @@ corefile_open(const char *comm, uid_t uid, pid_t pid, oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); flags = O_CREAT | FWRITE | O_NOFOLLOW; + if ((td->td_proc->p_flag & P_SUGID) != 0) + flags |= O_EXCL; NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, @@ -3599,10 +3607,11 @@ coredump(struct thread *td) /* * Don't dump to non-regular files or files with links. - * Do not dump into system files. + * Do not dump into system files. Effective user must own the corefile. */ if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || - vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { + vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || + vattr.va_uid != cred->cr_uid) { VOP_UNLOCK(vp, 0); error = EFAULT; goto out;