From patchwork Thu Oct 29 00:32:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11864477 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EED846A2 for ; Thu, 29 Oct 2020 00:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D672921534 for ; Thu, 29 Oct 2020 00:39:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388798AbgJ2Aji (ORCPT ); Wed, 28 Oct 2020 20:39:38 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:33327 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388782AbgJ2AjH (ORCPT ); Wed, 28 Oct 2020 20:39:07 -0400 Received: from ip5f5af0a0.dynamic.kabel-deutschland.de ([95.90.240.160] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kXvuz-0008Ep-Kw; Thu, 29 Oct 2020 00:35:53 +0000 From: Christian Brauner To: Alexander Viro , Christoph Hellwig , linux-fsdevel@vger.kernel.org Cc: John Johansen , James Morris , Mimi Zohar , Dmitry Kasatkin , Stephen Smalley , Casey Schaufler , Arnd Bergmann , Andreas Dilger , OGAWA Hirofumi , Geoffrey Thomas , Mrunal Patel , Josh Triplett , Andy Lutomirski , Amir Goldstein , Miklos Szeredi , Theodore Tso , Alban Crequy , Tycho Andersen , David Howells , James Bottomley , Jann Horn , Seth Forshee , =?utf-8?q?St=C3=A9phane_Graber?= , Aleksa Sarai , Lennart Poettering , "Eric W. Biederman" , smbarber@chromium.org, Phil Estes , Serge Hallyn , Kees Cook , Todd Kjos , Jonathan Corbet , containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, linux-ext4@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-audit@redhat.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, Christian Brauner Subject: [PATCH 24/34] would_dump: handle idmapped mounts Date: Thu, 29 Oct 2020 01:32:42 +0100 Message-Id: <20201029003252.2128653-25-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.29.0 In-Reply-To: <20201029003252.2128653-1-christian.brauner@ubuntu.com> References: <20201029003252.2128653-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org When determining whether or not to create a coredump the vfs will verify that the caller is privileged over the inode. Make the would_dump() helper handle idmapped mounts by passing down the mount's user namespace of the exec file. Signed-off-by: Christian Brauner --- fs/exec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 8e75d7a33514..76de175eeba8 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1391,14 +1391,15 @@ EXPORT_SYMBOL(begin_new_exec); void would_dump(struct linux_binprm *bprm, struct file *file) { struct inode *inode = file_inode(file); - if (inode_permission(inode, MAY_READ) < 0) { + struct user_namespace *ns = mnt_user_ns(file->f_path.mnt); + if (mapped_inode_permission(ns, inode, MAY_READ) < 0) { struct user_namespace *old, *user_ns; bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; /* Ensure mm->user_ns contains the executable */ user_ns = old = bprm->mm->user_ns; while ((user_ns != &init_user_ns) && - !privileged_wrt_inode_uidgid(user_ns, &init_user_ns, inode)) + !privileged_wrt_inode_uidgid(user_ns, ns, inode)) user_ns = user_ns->parent; if (old != user_ns) {