From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua0-f199.google.com (mail-ua0-f199.google.com [209.85.217.199]) by kanga.kvack.org (Postfix) with ESMTP id 7D9046B0266 for ; Mon, 30 Jan 2017 22:56:26 -0500 (EST) Received: by mail-ua0-f199.google.com with SMTP id j94so211887662uad.0 for ; Mon, 30 Jan 2017 19:56:26 -0800 (PST) Received: from mail-ua0-x229.google.com (mail-ua0-x229.google.com. [2607:f8b0:400c:c08::229]) by mx.google.com with ESMTPS id q9si4417291uaf.142.2017.01.30.19.56.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 Jan 2017 19:56:25 -0800 (PST) Received: by mail-ua0-x229.google.com with SMTP id i68so264375819uad.0 for ; Mon, 30 Jan 2017 19:56:25 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: From: Andy Lutomirski Date: Mon, 30 Jan 2017 19:56:04 -0800 Message-ID: Subject: Re: [PATCH v2 0/2] setgid hardening Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Michael Kerrisk Cc: Andy Lutomirski , "security@kernel.org" , Konstantin Khlebnikov , Alexander Viro , Kees Cook , Willy Tarreau , "linux-mm@kvack.org" , Andrew Morton , yalin wang , Linux Kernel Mailing List , Jan Kara , Linux FS Devel , Frank Filz , Linux API On Mon, Jan 30, 2017 at 7:49 PM, Michael Kerrisk wrote: > [CC += linux-api@] > > Andy, this is an API change! Indeed. I should be ashamed of myself! > > On Sat, Jan 28, 2017 at 3:49 PM, Andy Lutomirski wrote: >> The kernel has some dangerous behavior involving the creation and >> modification of setgid executables. These issues aren't kernel >> security bugs per se, but they have been used to turn various >> filesystem permission oddities into reliably privilege escalation >> exploits. >> >> See http://www.halfdog.net/Security/2015/SetgidDirectoryPrivilegeEscalation/ >> for a nice writeup. >> >> Let's fix them for real. >> >> Changes from v1: >> - Fix uninitialized variable issue (Willy, Ben) >> - Also check current creds in should_remove_suid() (Ben) >> >> Andy Lutomirski (2): >> fs: Check f_cred as well as of current's creds in should_remove_suid() >> fs: Harden against open(..., O_CREAT, 02777) in a setgid directory >> >> fs/inode.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++-------- >> fs/internal.h | 2 +- >> fs/ocfs2/file.c | 4 ++-- >> fs/open.c | 2 +- >> include/linux/fs.h | 2 +- >> 5 files changed, 57 insertions(+), 14 deletions(-) >> >> -- >> 2.9.3 >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: email@kvack.org > > > > -- > Michael Kerrisk Linux man-pages maintainer; > http://www.kernel.org/doc/man-pages/ > Author of "The Linux Programming Interface", http://blog.man7.org/ -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org