linux-kernel - [PATCH 4.4 338/342] security: let security modules use PTRACE_MODE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20160301234538.788825162@linuxfoundation.org>
Date:	Tue, 01 Mar 2016 23:55:37 +0000
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	<linux-kernel@...r.kernel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<stable@...r.kernel.org>, Jann Horn <jann@...jh.net>,
	Kees Cook <keescook@...omium.org>,
	Casey Schaufler <casey@...aufler-ca.com>,
	Oleg Nesterov <oleg@...hat.com>,
	Ingo Molnar <mingo@...hat.com>,
	James Morris <james.l.morris@...cle.com>,
	"Serge E. Hallyn" <serge.hallyn@...ntu.com>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Andy Lutomirski <luto@...nel.org>,
	Al Viro <viro@...iv.linux.org.uk>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Willy Tarreau <w@....eu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [PATCH 4.4 338/342] security: let security modules use PTRACE_MODE_* with bitmasks

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jann Horn <jann@...jh.net>

commit 3dfb7d8cdbc7ea0c2970450e60818bb3eefbad69 upstream.

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 <jann@...jh.net>
Acked-by: Kees Cook <keescook@...omium.org>
Acked-by: Casey Schaufler <casey@...aufler-ca.com>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: James Morris <james.l.morris@...cle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@...ntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Al Viro <viro@...iv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@...ssion.com>
Cc: Willy Tarreau <w@....eu>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 security/smack/smack_lsm.c |    8 +++-----
 security/yama/yama_lsm.c   |    4 ++--
 2 files changed, 5 insertions(+), 7 deletions(-)

--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -398,12 +398,10 @@ static int smk_copy_relabel(struct list_
  */
 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;
 }
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -281,7 +281,7 @@ static int yama_ptrace_access_check(stru
 	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(stru
 		}
 	}

-	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);