Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753103Ab3JAUeE (ORCPT ); Tue, 1 Oct 2013 16:34:04 -0400 Received: from numidia.opendz.org ([98.142.220.152]:55540 "EHLO numidia.opendz.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751077Ab3JAUeC (ORCPT ); Tue, 1 Oct 2013 16:34:02 -0400 From: Djalal Harouni To: "Eric W. Biederman" , Kees Cook , Al Viro , Andrew Morton , Linus Torvalds , Ingo Molnar , "Serge E. Hallyn" , Cyrill Gorcunov , David Rientjes , LKML , linux-fsdevel@vger.kernel.org, kernel-hardening@lists.openwall.com Cc: tixxdz@gmail.com, Djalal Harouni Subject: [PATCH v2 7/9] procfs: add permission checks on the file's opener of /proc/*/personality Date: Tue, 1 Oct 2013 21:26:16 +0100 Message-Id: <1380659178-28605-8-git-send-email-tixxdz@opendz.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1380659178-28605-1-git-send-email-tixxdz@opendz.org> References: <1380659178-28605-1-git-send-email-tixxdz@opendz.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1515 Lines: 50 If current's cred have changed between ->open() and ->read(), then call proc_allow_access() to check if the original file's opener had enough permissions to access the /proc/*/personality entry during ->read(). Cc: Kees Cook Cc: Eric W. Biederman Signed-off-by: Djalal Harouni --- fs/proc/base.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index d4b604d..77f5b84 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2647,11 +2647,23 @@ static const struct file_operations proc_projid_map_operations = { static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { + struct file *file = m->private; + const struct cred *fcred = file->f_cred; + int same_cred = proc_same_open_cred(fcred); int err = lock_trace(task); - if (!err) { - seq_printf(m, "%08x\n", task->personality); - unlock_trace(task); + if (err) + return err; + + if (!same_cred && + !proc_allow_access(fcred, task, PTRACE_MODE_ATTACH)) { + err = -EPERM; + goto out; } + + seq_printf(m, "%08x\n", task->personality); + +out: + unlock_trace(task); return err; } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/