Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/…

…jmorris/linux-security

Pull security subsystem updates for 3.4 from James Morris:
 "The main addition here is the new Yama security module from Kees Cook,
  which was discussed at the Linux Security Summit last year.  Its
  purpose is to collect miscellaneous DAC security enhancements in one
  place.  This also marks a departure in policy for LSM modules, which
  were previously limited to being standalone access control systems.
  Chromium OS is using Yama, and I believe there are plans for Ubuntu,
  at least.

  This patchset also includes maintenance updates for AppArmor, TOMOYO
  and others."

Fix trivial conflict in <net/sock.h> due to the jumo_label->static_key
rename.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
  AppArmor: Fix location of const qualifier on generated string tables
  TOMOYO: Return error if fails to delete a domain
  AppArmor: add const qualifiers to string arrays
  AppArmor: Add ability to load extended policy
  TOMOYO: Return appropriate value to poll().
  AppArmor: Move path failure information into aa_get_name and rename
  AppArmor: Update dfa matching routines.
  AppArmor: Minor cleanup of d_namespace_path to consolidate error handling
  AppArmor: Retrieve the dentry_path for error reporting when path lookup fails
  AppArmor: Add const qualifiers to generated string tables
  AppArmor: Fix oops in policy unpack auditing
  AppArmor: Fix error returned when a path lookup is disconnected
  KEYS: testing wrong bit for KEY_FLAG_REVOKED
  TOMOYO: Fix mount flags checking order.
  security: fix ima kconfig warning
  AppArmor: Fix the error case for chroot relative path name lookup
  AppArmor: fix mapping of META_READ to audit and quiet flags
  AppArmor: Fix underflow in xindex calculation
  AppArmor: Fix dropping of allowed operations that are force audited
  AppArmor: Add mising end of structure test to caps unpacking
  ...

Documentation/networking/dns_resolver.txt

@@ -102,6 +102,10 @@ implemented in the module can be called after doing:
      If _expiry is non-NULL, the expiry time (TTL) of the result will be
      returned also.
 
+The kernel maintains an internal keyring in which it caches looked up keys.
+This can be cleared by any process that has the CAP_SYS_ADMIN capability by
+the use of KEYCTL_KEYRING_CLEAR on the keyring ID.
+
 
 ===============================
 READING DNS KEYS FROM USERSPACE

Documentation/security/00-INDEX

@@ -6,6 +6,8 @@ SELinux.txt
 	- how to get started with the SELinux security enhancement.
 Smack.txt
 	- documentation on the Smack Linux Security Module.
+Yama.txt
+	- documentation on the Yama Linux Security Module.
 apparmor.txt
 	- documentation on the AppArmor security extension.
 credentials.txt

Documentation/security/Yama.txt

@@ -0,0 +1,65 @@
+Yama is a Linux Security Module that collects a number of system-wide DAC
+security protections that are not handled by the core kernel itself. To
+select it at boot time, specify "security=yama" (though this will disable
+any other LSM).
+
+Yama is controlled through sysctl in /proc/sys/kernel/yama:
+
+- ptrace_scope
+
+==============================================================
+
+ptrace_scope:
+
+As Linux grows in popularity, it will become a larger target for
+malware. One particularly troubling weakness of the Linux process
+interfaces is that a single user is able to examine the memory and
+running state of any of their processes. For example, if one application
+(e.g. Pidgin) was compromised, it would be possible for an attacker to
+attach to other running processes (e.g. Firefox, SSH sessions, GPG agent,
+etc) to extract additional credentials and continue to expand the scope
+of their attack without resorting to user-assisted phishing.
+
+This is not a theoretical problem. SSH session hijacking
+(http://www.storm.net.nz/projects/7) and arbitrary code injection
+(http://c-skills.blogspot.com/2007/05/injectso.html) attacks already
+exist and remain possible if ptrace is allowed to operate as before.
+Since ptrace is not commonly used by non-developers and non-admins, system
+builders should be allowed the option to disable this debugging system.
+
+For a solution, some applications use prctl(PR_SET_DUMPABLE, ...) to
+specifically disallow such ptrace attachment (e.g. ssh-agent), but many
+do not. A more general solution is to only allow ptrace directly from a
+parent to a child process (i.e. direct "gdb EXE" and "strace EXE" still
+work), or with CAP_SYS_PTRACE (i.e. "gdb --pid=PID", and "strace -p PID"
+still work as root).
+
+For software that has defined application-specific relationships
+between a debugging process and its inferior (crash handlers, etc),
+prctl(PR_SET_PTRACER, pid, ...) can be used. An inferior can declare which
+other process (and its descendents) are allowed to call PTRACE_ATTACH
+against it. Only one such declared debugging process can exists for
+each inferior at a time. For example, this is used by KDE, Chromium, and
+Firefox's crash handlers, and by Wine for allowing only Wine processes
+to ptrace each other. If a process wishes to entirely disable these ptrace
+restrictions, it can call prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, ...)
+so that any otherwise allowed process (even those in external pid namespaces)
+may attach.
+
+The sysctl settings are:
+
+0 - classic ptrace permissions: a process can PTRACE_ATTACH to any other
+    process running under the same uid, as long as it is dumpable (i.e.
+    did not transition uids, start privileged, or have called
+    prctl(PR_SET_DUMPABLE...) already).
+
+1 - restricted ptrace: a process must have a predefined relationship
+    with the inferior it wants to call PTRACE_ATTACH on. By default,
+    this relationship is that of only its descendants when the above
+    classic criteria is also met. To change the relationship, an
+    inferior can call prctl(PR_SET_PTRACER, debugger, ...) to declare
+    an allowed debugger PID to call PTRACE_ATTACH on the inferior.
+
+The original children-only logic was based on the restrictions in grsecurity.
+
+==============================================================

Documentation/security/keys.txt

@@ -554,6 +554,10 @@ The keyctl syscall functions are:
      process must have write permission on the keyring, and it must be a
      keyring (or else error ENOTDIR will result).
 
+     This function can also be used to clear special kernel keyrings if they
+     are appropriately marked if the user has CAP_SYS_ADMIN capability.  The
+     DNS resolver cache keyring is an example of this.
+
 
  (*) Link a key into a keyring:
 

drivers/char/tpm/Kconfig

@@ -5,7 +5,6 @@
 menuconfig TCG_TPM
 	tristate "TPM Hardware Support"
 	depends on HAS_IOMEM
-	depends on EXPERIMENTAL
 	select SECURITYFS
 	---help---
 	  If you have a TPM security chip in your system, which

drivers/char/tpm/tpm.c

@@ -1221,12 +1221,13 @@ ssize_t tpm_read(struct file *file, char __user *buf,
 	ret_size = atomic_read(&chip->data_pending);
 	atomic_set(&chip->data_pending, 0);
 	if (ret_size > 0) {	/* relay data */
+		ssize_t orig_ret_size = ret_size;
 		if (size < ret_size)
 			ret_size = size;
 
 		mutex_lock(&chip->buffer_mutex);
 		rc = copy_to_user(buf, chip->data_buffer, ret_size);
-		memset(chip->data_buffer, 0, ret_size);
+		memset(chip->data_buffer, 0, orig_ret_size);
 		if (rc)
 			ret_size = -EFAULT;
 

drivers/char/tpm/tpm.h

@@ -99,6 +99,8 @@ struct tpm_vendor_specific {
 	wait_queue_head_t int_queue;
 };
 
+#define TPM_VID_INTEL    0x8086
+
 struct tpm_chip {
 	struct device *dev;	/* Device stuff */
 

drivers/char/tpm/tpm_tis.c

@@ -367,7 +367,12 @@ static int probe_itpm(struct tpm_chip *chip)
 		0x00, 0x00, 0x00, 0xf1
 	};
 	size_t len = sizeof(cmd_getticks);
-	int rem_itpm = itpm;
+	bool rem_itpm = itpm;
+	u16 vendor = ioread16(chip->vendor.iobase + TPM_DID_VID(0));
+
+	/* probe only iTPMS */
+	if (vendor != TPM_VID_INTEL)
+		return 0;
 
 	itpm = 0;
 
@@ -390,9 +395,6 @@ static int probe_itpm(struct tpm_chip *chip)
 out:
 	itpm = rem_itpm;
 	tpm_tis_ready(chip);
-	/* some TPMs need a break here otherwise they will not work
-	 * correctly on the immediately subsequent command */
-	msleep(chip->vendor.timeout_b);
 	release_locality(chip, chip->vendor.locality, 0);
 
 	return rc;
@@ -508,7 +510,7 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
 			resource_size_t len, unsigned int irq)
 {
 	u32 vendor, intfcaps, intmask;
-	int rc, i, irq_s, irq_e;
+	int rc, i, irq_s, irq_e, probe;
 	struct tpm_chip *chip;
 
 	if (!(chip = tpm_register_hardware(dev, &tpm_tis)))
@@ -538,11 +540,12 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
 		 vendor >> 16, ioread8(chip->vendor.iobase + TPM_RID(0)));
 
 	if (!itpm) {
-		itpm = probe_itpm(chip);
-		if (itpm < 0) {
+		probe = probe_itpm(chip);
+		if (probe < 0) {
 			rc = -ENODEV;
 			goto out_err;
 		}
+		itpm = (probe == 0) ? 0 : 1;
 	}
 
 	if (itpm)

drivers/net/macvtap.c

@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/wait.h>
 #include <linux/cdev.h>
+#include <linux/idr.h>
 #include <linux/fs.h>
 
 #include <net/net_namespace.h>

drivers/target/iscsi/iscsi_target.c

@@ -23,6 +23,7 @@
 #include <linux/crypto.h>
 #include <linux/completion.h>
 #include <linux/module.h>
+#include <linux/idr.h>
 #include <asm/unaligned.h>
 #include <scsi/scsi_device.h>
 #include <scsi/iscsi_proto.h>

drivers/target/iscsi/iscsi_target_login.c

@@ -21,6 +21,7 @@
 #include <linux/string.h>
 #include <linux/kthread.h>
 #include <linux/crypto.h>
+#include <linux/idr.h>
 #include <scsi/iscsi_proto.h>
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>

fs/cifs/cifsacl.c

@@ -556,6 +556,7 @@ init_cifs_idmap(void)
 
 	/* instruct request_key() to use this special keyring as a cache for
 	 * the results it looks up */
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 	cred->thread_keyring = keyring;
 	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 	root_cred = cred;

fs/nfs/client.c

@@ -36,6 +36,7 @@
 #include <linux/inet.h>
 #include <linux/in6.h>
 #include <linux/slab.h>
+#include <linux/idr.h>
 #include <net/ipv6.h>
 #include <linux/nfs_xdr.h>
 #include <linux/sunrpc/bc_xprt.h>

fs/nfs/idmap.c

@@ -198,6 +198,7 @@ int nfs_idmap_init(void)
 	if (ret < 0)
 		goto failed_put_key;
 
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 	cred->thread_keyring = keyring;
 	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 	id_resolver_cache = cred;

fs/proc/proc_sysctl.c

@@ -6,7 +6,9 @@
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/security.h>
+#include <linux/sched.h>
 #include <linux/namei.h>
+#include <linux/mm.h>
 #include "internal.h"
 
 static const struct dentry_operations proc_sys_dentry_operations;

fs/quota/dquot.c

@@ -71,6 +71,7 @@
 #include <linux/module.h>
 #include <linux/proc_fs.h>
 #include <linux/security.h>
+#include <linux/sched.h>
 #include <linux/kmod.h>
 #include <linux/namei.h>
 #include <linux/capability.h>

fs/super.c

@@ -32,6 +32,7 @@
 #include <linux/backing-dev.h>
 #include <linux/rculist_bl.h>
 #include <linux/cleancache.h>
+#include <linux/fsnotify.h>
 #include "internal.h"
 
 

include/linux/key.h

@@ -155,6 +155,7 @@ struct key {
 #define KEY_FLAG_IN_QUOTA	3	/* set if key consumes quota */
 #define KEY_FLAG_USER_CONSTRUCT	4	/* set if key is being constructed in userspace */
 #define KEY_FLAG_NEGATIVE	5	/* set if key is negative */
+#define KEY_FLAG_ROOT_CAN_CLEAR	6	/* set if key can be cleared by root without permission */
 
 	/* the description string
 	 * - this is used to match a key against search criteria

include/linux/prctl.h

@@ -114,4 +114,11 @@
 # define PR_SET_MM_START_BRK		6
 # define PR_SET_MM_BRK			7
 
+/*
+ * Set specific pid that is allowed to ptrace the current task.
+ * A value of 0 mean "no process".
+ */
+#define PR_SET_PTRACER 0x59616d61
+# define PR_SET_PTRACER_ANY ((unsigned long)-1)
+
 #endif /* _LINUX_PRCTL_H */