From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f170.google.com (mail-qk0-f170.google.com [209.85.220.170]) by kanga.kvack.org (Postfix) with ESMTP id 659126B0278 for ; Mon, 7 Dec 2015 16:52:01 -0500 (EST) Received: by qkfb125 with SMTP id b125so1262678qkf.2 for ; Mon, 07 Dec 2015 13:52:01 -0800 (PST) Received: from nm18-vm0.bullet.mail.bf1.yahoo.com (nm18-vm0.bullet.mail.bf1.yahoo.com. [98.139.213.138]) by mx.google.com with ESMTPS id b79si46855qga.92.2015.12.07.13.52.00 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 07 Dec 2015 13:52:00 -0800 (PST) Subject: Re: [PATCH 1/2] security: let security modules use PTRACE_MODE_* with bitmasks References: <20151207203824.GA27364@pc.thejh.net> <1449523512-29200-1-git-send-email-jann@thejh.net> <1449523512-29200-2-git-send-email-jann@thejh.net> From: Casey Schaufler Message-ID: <5665FF76.5090701@schaufler-ca.com> Date: Mon, 7 Dec 2015 13:51:50 -0800 MIME-Version: 1.0 In-Reply-To: <1449523512-29200-2-git-send-email-jann@thejh.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jann Horn , Andrew Morton , Kees Cook Cc: Oleg Nesterov , Ingo Molnar , James Morris , "Serge E. Hallyn" , Andy Shevchenko , Andy Lutomirski , Al Viro , "Eric W. Biederman" , Joe Perches , Thomas Gleixner , Michael Kerrisk , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, security@kernel.org, Willy Tarreau On 12/7/2015 1:25 PM, Jann Horn wrote: > It looks like smack and yama weren't aware that the ptrace mode > can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but > only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch, > all modes have flags ORed into them. > > Signed-off-by: Jann Horn Acked-by: Casey Schaufler > --- > security/smack/smack_lsm.c | 8 +++----- > security/yama/yama_lsm.c | 4 ++-- > 2 files changed, 5 insertions(+), 7 deletions(-) > > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index ff81026..7c57c7f 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -398,12 +398,10 @@ static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, > */ > static inline unsigned int smk_ptrace_mode(unsigned int mode) > { > - switch (mode) { > - case PTRACE_MODE_READ: > - return MAY_READ; > - case PTRACE_MODE_ATTACH: > + if (mode & PTRACE_MODE_ATTACH) > return MAY_READWRITE; > - } > + if (mode & PTRACE_MODE_READ) > + return MAY_READ; > > return 0; > } > diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c > index d3c19c9..cb6ed10 100644 > --- a/security/yama/yama_lsm.c > +++ b/security/yama/yama_lsm.c > @@ -281,7 +281,7 @@ static int yama_ptrace_access_check(struct task_struct *child, > int rc = 0; > > /* require ptrace target be a child of ptracer on attach */ > - if (mode == PTRACE_MODE_ATTACH) { > + if (mode & PTRACE_MODE_ATTACH) { > switch (ptrace_scope) { > case YAMA_SCOPE_DISABLED: > /* No additional restrictions. */ > @@ -307,7 +307,7 @@ static int yama_ptrace_access_check(struct task_struct *child, > } > } > > - if (rc) { > + if (rc && (mode & PTRACE_MODE_NOAUDIT) == 0) { > printk_ratelimited(KERN_NOTICE > "ptrace of pid %d was attempted by: %s (pid %d)\n", > child->pid, current->comm, current->pid); -- 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