Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (38 commits)
  SELinux: Make selinux_kernel_create_files_as() shouldn't just always return 0
  TOMOYO: Protect find_task_by_vpid() with RCU.
  Security: add static to security_ops and default_security_ops variable
  selinux: libsepol: remove dead code in check_avtab_hierarchy_callback()
  TOMOYO: Remove __func__ from tomoyo_is_correct_path/domain
  security: fix a couple of sparse warnings
  TOMOYO: Remove unneeded parameter.
  TOMOYO: Use shorter names.
  TOMOYO: Use enum for index numbers.
  TOMOYO: Add garbage collector.
  TOMOYO: Add refcounter on domain structure.
  TOMOYO: Merge headers.
  TOMOYO: Add refcounter on string data.
  TOMOYO: Reduce lines by using common path for addition and deletion.
  selinux: fix memory leak in sel_make_bools
  TOMOYO: Extract bitfield
  syslog: clean up needless comment
  syslog: use defined constants instead of raw numbers
  syslog: distinguish between /proc/kmsg and syscalls
  selinux: allow MLS->non-MLS and vice versa upon policy reload
  ...

fs/proc/kmsg.c

@@ -12,37 +12,37 @@
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/fs.h>
+#include <linux/syslog.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
 extern wait_queue_head_t log_wait;
 
-extern int do_syslog(int type, char __user *bug, int count);
-
 static int kmsg_open(struct inode * inode, struct file * file)
 {
-	return do_syslog(1,NULL,0);
+	return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_FILE);
 }
 
 static int kmsg_release(struct inode * inode, struct file * file)
 {
-	(void) do_syslog(0,NULL,0);
+	(void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_FILE);
 	return 0;
 }
 
 static ssize_t kmsg_read(struct file *file, char __user *buf,
 			 size_t count, loff_t *ppos)
 {
-	if ((file->f_flags & O_NONBLOCK) && !do_syslog(9, NULL, 0))
+	if ((file->f_flags & O_NONBLOCK) &&
+	    !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_FILE))
 		return -EAGAIN;
-	return do_syslog(2, buf, count);
+	return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_FILE);
 }
 
 static unsigned int kmsg_poll(struct file *file, poll_table *wait)
 {
 	poll_wait(file, &log_wait, wait);
-	if (do_syslog(9, NULL, 0))
+	if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_FILE))
 		return POLLIN | POLLRDNORM;
 	return 0;
 }

include/linux/security.h

@@ -76,7 +76,7 @@ extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 extern int cap_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp);
 extern int cap_task_setioprio(struct task_struct *p, int ioprio);
 extern int cap_task_setnice(struct task_struct *p, int nice);
-extern int cap_syslog(int type);
+extern int cap_syslog(int type, bool from_file);
 extern int cap_vm_enough_memory(struct mm_struct *mm, long pages);
 
 struct msghdr;
@@ -95,6 +95,8 @@ struct seq_file;
 extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
 extern int cap_netlink_recv(struct sk_buff *skb, int cap);
 
+void reset_security_ops(void);
+
 #ifdef CONFIG_MMU
 extern unsigned long mmap_min_addr;
 extern unsigned long dac_mmap_min_addr;
@@ -985,6 +987,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *	Check permissions on incoming network packets.  This hook is distinct
  *	from Netfilter's IP input hooks since it is the first time that the
  *	incoming sk_buff @skb has been associated with a particular socket, @sk.
+ *	Must not sleep inside this hook because some callers hold spinlocks.
  *	@sk contains the sock (not socket) associated with the incoming sk_buff.
  *	@skb contains the incoming network data.
  * @socket_getpeersec_stream:
@@ -1348,6 +1351,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *	logging to the console.
  *	See the syslog(2) manual page for an explanation of the @type values.
  *	@type contains the type of action.
+ *	@from_file indicates the context of action (if it came from /proc).
  *	Return 0 if permission is granted.
  * @settime:
  *	Check permission to change the system time.
@@ -1462,7 +1466,7 @@ struct security_operations {
 	int (*sysctl) (struct ctl_table *table, int op);
 	int (*quotactl) (int cmds, int type, int id, struct super_block *sb);
 	int (*quota_on) (struct dentry *dentry);
-	int (*syslog) (int type);
+	int (*syslog) (int type, bool from_file);
 	int (*settime) (struct timespec *ts, struct timezone *tz);
 	int (*vm_enough_memory) (struct mm_struct *mm, long pages);
 
@@ -1761,7 +1765,7 @@ int security_acct(struct file *file);
 int security_sysctl(struct ctl_table *table, int op);
 int security_quotactl(int cmds, int type, int id, struct super_block *sb);
 int security_quota_on(struct dentry *dentry);
-int security_syslog(int type);
+int security_syslog(int type, bool from_file);
 int security_settime(struct timespec *ts, struct timezone *tz);
 int security_vm_enough_memory(long pages);
 int security_vm_enough_memory_mm(struct mm_struct *mm, long pages);
@@ -2007,9 +2011,9 @@ static inline int security_quota_on(struct dentry *dentry)
 	return 0;
 }
 
-static inline int security_syslog(int type)
+static inline int security_syslog(int type, bool from_file)
 {
-	return cap_syslog(type);
+	return cap_syslog(type, from_file);
 }
 
 static inline int security_settime(struct timespec *ts, struct timezone *tz)

include/linux/syslog.h

@@ -0,0 +1,52 @@
+/*  Syslog internals
+ *
+ *  Copyright 2010 Canonical, Ltd.
+ *  Author: Kees Cook <kees.cook@canonical.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2, or (at your option)
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _LINUX_SYSLOG_H
+#define _LINUX_SYSLOG_H
+
+/* Close the log.  Currently a NOP. */
+#define SYSLOG_ACTION_CLOSE          0
+/* Open the log. Currently a NOP. */
+#define SYSLOG_ACTION_OPEN           1
+/* Read from the log. */
+#define SYSLOG_ACTION_READ           2
+/* Read all messages remaining in the ring buffer. */
+#define SYSLOG_ACTION_READ_ALL       3
+/* Read and clear all messages remaining in the ring buffer */
+#define SYSLOG_ACTION_READ_CLEAR     4
+/* Clear ring buffer. */
+#define SYSLOG_ACTION_CLEAR          5
+/* Disable printk's to console */
+#define SYSLOG_ACTION_CONSOLE_OFF    6
+/* Enable printk's to console */
+#define SYSLOG_ACTION_CONSOLE_ON     7
+/* Set level of messages printed to console */
+#define SYSLOG_ACTION_CONSOLE_LEVEL  8
+/* Return number of unread characters in the log buffer */
+#define SYSLOG_ACTION_SIZE_UNREAD    9
+/* Return size of the log buffer */
+#define SYSLOG_ACTION_SIZE_BUFFER   10
+
+#define SYSLOG_FROM_CALL 0
+#define SYSLOG_FROM_FILE 1
+
+int do_syslog(int type, char __user *buf, int count, bool from_file);
+
+#endif /* _LINUX_SYSLOG_H */

kernel/capability.c

@@ -135,15 +135,15 @@ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
 	if (pid && (pid != task_pid_vnr(current))) {
 		struct task_struct *target;
 
-		read_lock(&tasklist_lock);
+		rcu_read_lock();
 
 		target = find_task_by_vpid(pid);
 		if (!target)
 			ret = -ESRCH;
 		else
 			ret = security_capget(target, pEp, pIp, pPp);
 
-		read_unlock(&tasklist_lock);
+		rcu_read_unlock();
 	} else
 		ret = security_capget(current, pEp, pIp, pPp);
 

kernel/printk.c

@@ -35,6 +35,7 @@
 #include <linux/kexec.h>
 #include <linux/ratelimit.h>
 #include <linux/kmsg_dump.h>
+#include <linux/syslog.h>
 
 #include <asm/uaccess.h>
 
@@ -258,38 +259,23 @@ static inline void boot_delay_msec(void)
 }
 #endif
 
-/*
- * Commands to do_syslog:
- *
- * 	0 -- Close the log.  Currently a NOP.
- * 	1 -- Open the log. Currently a NOP.
- * 	2 -- Read from the log.
- * 	3 -- Read all messages remaining in the ring buffer.
- * 	4 -- Read and clear all messages remaining in the ring buffer
- * 	5 -- Clear ring buffer.
- * 	6 -- Disable printk's to console
- * 	7 -- Enable printk's to console
- *	8 -- Set level of messages printed to console
- *	9 -- Return number of unread characters in the log buffer
- *     10 -- Return size of the log buffer
- */
-int do_syslog(int type, char __user *buf, int len)
+int do_syslog(int type, char __user *buf, int len, bool from_file)
 {
 	unsigned i, j, limit, count;
 	int do_clear = 0;
 	char c;
 	int error = 0;
 
-	error = security_syslog(type);
+	error = security_syslog(type, from_file);
 	if (error)
 		return error;
 
 	switch (type) {
-	case 0:		/* Close log */
+	case SYSLOG_ACTION_CLOSE:	/* Close log */
 		break;
-	case 1:		/* Open log */
+	case SYSLOG_ACTION_OPEN:	/* Open log */
 		break;
-	case 2:		/* Read from log */
+	case SYSLOG_ACTION_READ:	/* Read from log */
 		error = -EINVAL;
 		if (!buf || len < 0)
 			goto out;
@@ -320,10 +306,12 @@ int do_syslog(int type, char __user *buf, int len)
 		if (!error)
 			error = i;
 		break;
-	case 4:		/* Read/clear last kernel messages */
+	/* Read/clear last kernel messages */
+	case SYSLOG_ACTION_READ_CLEAR:
 		do_clear = 1;
 		/* FALL THRU */
-	case 3:		/* Read last kernel messages */
+	/* Read last kernel messages */
+	case SYSLOG_ACTION_READ_ALL:
 		error = -EINVAL;
 		if (!buf || len < 0)
 			goto out;
@@ -376,21 +364,25 @@ int do_syslog(int type, char __user *buf, int len)
 			}
 		}
 		break;
-	case 5:		/* Clear ring buffer */
+	/* Clear ring buffer */
+	case SYSLOG_ACTION_CLEAR:
 		logged_chars = 0;
 		break;
-	case 6:		/* Disable logging to console */
+	/* Disable logging to console */
+	case SYSLOG_ACTION_CONSOLE_OFF:
 		if (saved_console_loglevel == -1)
 			saved_console_loglevel = console_loglevel;
 		console_loglevel = minimum_console_loglevel;
 		break;
-	case 7:		/* Enable logging to console */
+	/* Enable logging to console */
+	case SYSLOG_ACTION_CONSOLE_ON:
 		if (saved_console_loglevel != -1) {
 			console_loglevel = saved_console_loglevel;
 			saved_console_loglevel = -1;
 		}
 		break;
-	case 8:		/* Set level of messages printed to console */
+	/* Set level of messages printed to console */
+	case SYSLOG_ACTION_CONSOLE_LEVEL:
 		error = -EINVAL;
 		if (len < 1 || len > 8)
 			goto out;
@@ -401,10 +393,12 @@ int do_syslog(int type, char __user *buf, int len)
 		saved_console_loglevel = -1;
 		error = 0;
 		break;
-	case 9:		/* Number of chars in the log buffer */
+	/* Number of chars in the log buffer */
+	case SYSLOG_ACTION_SIZE_UNREAD:
 		error = log_end - log_start;
 		break;
-	case 10:	/* Size of the log buffer */
+	/* Size of the log buffer */
+	case SYSLOG_ACTION_SIZE_BUFFER:
 		error = log_buf_len;
 		break;
 	default:
@@ -417,7 +411,7 @@ int do_syslog(int type, char __user *buf, int len)
 
 SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
 {
-	return do_syslog(type, buf, len);
+	return do_syslog(type, buf, len, SYSLOG_FROM_CALL);
 }
 
 /*

security/capability.c

@@ -906,10 +906,6 @@ static void cap_audit_rule_free(void *lsmrule)
 }
 #endif /* CONFIG_AUDIT */
 
-struct security_operations default_security_ops = {
-	.name	= "default",
-};
-
 #define set_to_cap_if_null(ops, function)				\
 	do {								\
 		if (!ops->function) {					\

security/commoncap.c

@@ -27,6 +27,7 @@
 #include <linux/sched.h>
 #include <linux/prctl.h>
 #include <linux/securebits.h>
+#include <linux/syslog.h>
 
 /*
  * If a non-root user executes a setuid-root binary in
@@ -888,13 +889,17 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 /**
  * cap_syslog - Determine whether syslog function is permitted
  * @type: Function requested
+ * @from_file: Whether this request came from an open file (i.e. /proc)
  *
  * Determine whether the current process is permitted to use a particular
  * syslog function, returning 0 if permission is granted, -ve if not.
  */
-int cap_syslog(int type)
+int cap_syslog(int type, bool from_file)
 {
-	if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN))
+	if (type != SYSLOG_ACTION_OPEN && from_file)
+		return 0;
+	if ((type != SYSLOG_ACTION_READ_ALL &&
+	     type != SYSLOG_ACTION_SIZE_BUFFER) && !capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	return 0;
 }