Merge branch 'next' into for-linus

fs/binfmt_flat.c

@@ -820,6 +820,8 @@ static int load_flat_shared_library(int id, struct lib_info *libs)
 	int res;
 	char buf[16];
 
+	memset(&bprm, 0, sizeof(bprm));
+
 	/* Create the file name */
 	sprintf(buf, "/lib/lib%d.so", id);
 
@@ -835,6 +837,12 @@ static int load_flat_shared_library(int id, struct lib_info *libs)
 	if (!bprm.cred)
 		goto out;
 
+	/* We don't really care about recalculating credentials at this point
+	 * as we're past the point of no return and are dealing with shared
+	 * libraries.
+	 */
+	bprm.cred_prepared = 1;
+
 	res = prepare_binprm(&bprm);
 
 	if (!IS_ERR_VALUE(res))

include/linux/capability.h

@@ -417,7 +417,6 @@ extern const kernel_cap_t __cap_init_eff_set;
 
 # define CAP_EMPTY_SET    ((kernel_cap_t){{ 0, 0 }})
 # define CAP_FULL_SET     ((kernel_cap_t){{ ~0, ~0 }})
-# define CAP_INIT_EFF_SET ((kernel_cap_t){{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }})
 # define CAP_FS_SET       ((kernel_cap_t){{ CAP_FS_MASK_B0 \
 				    | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
 				    CAP_FS_MASK_B1 } })
@@ -427,11 +426,7 @@ extern const kernel_cap_t __cap_init_eff_set;
 
 #endif /* _KERNEL_CAPABILITY_U32S != 2 */
 
-#define CAP_INIT_INH_SET    CAP_EMPTY_SET
-
 # define cap_clear(c)         do { (c) = __cap_empty_set; } while (0)
-# define cap_set_full(c)      do { (c) = __cap_full_set; } while (0)
-# define cap_set_init_eff(c)  do { (c) = __cap_init_eff_set; } while (0)
 
 #define cap_raise(c, flag)  ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag))
 #define cap_lower(c, flag)  ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))

include/linux/init_task.h

@@ -83,13 +83,6 @@ extern struct group_info init_groups;
 #define INIT_IDS
 #endif
 
-/*
- * Because of the reduced scope of CAP_SETPCAP when filesystem
- * capabilities are in effect, it is safe to allow CAP_SETPCAP to
- * be available in the default configuration.
- */
-# define CAP_INIT_BSET  CAP_FULL_SET
-
 #ifdef CONFIG_RCU_BOOST
 #define INIT_TASK_RCU_BOOST()						\
 	.rcu_boost_mutex = NULL,

include/linux/key.h

@@ -276,6 +276,19 @@ static inline key_serial_t key_serial(struct key *key)
 	return key ? key->serial : 0;
 }
 
+/**
+ * key_is_instantiated - Determine if a key has been positively instantiated
+ * @key: The key to check.
+ *
+ * Return true if the specified key has been positively instantiated, false
+ * otherwise.
+ */
+static inline bool key_is_instantiated(const struct key *key)
+{
+	return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
+		!test_bit(KEY_FLAG_NEGATIVE, &key->flags);
+}
+
 #define rcu_dereference_key(KEY)					\
 	(rcu_dereference_protected((KEY)->payload.rcudata,		\
 				   rwsem_is_locked(&((struct key *)(KEY))->sem)))

include/linux/kmod.h

@@ -24,6 +24,7 @@
 #include <linux/errno.h>
 #include <linux/compiler.h>
 #include <linux/workqueue.h>
+#include <linux/sysctl.h>
 
 #define KMOD_PATH_LEN 256
 
@@ -109,6 +110,8 @@ call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
 				       NULL, NULL, NULL);
 }
 
+extern struct ctl_table usermodehelper_table[];
+
 extern void usermodehelper_init(void);
 
 extern int usermodehelper_disable(void);

kernel/capability.c

@@ -22,12 +22,8 @@
  */
 
 const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET;
-const kernel_cap_t __cap_full_set = CAP_FULL_SET;
-const kernel_cap_t __cap_init_eff_set = CAP_INIT_EFF_SET;
 
 EXPORT_SYMBOL(__cap_empty_set);
-EXPORT_SYMBOL(__cap_full_set);
-EXPORT_SYMBOL(__cap_init_eff_set);
 
 int file_caps_enabled = 1;
 

kernel/cred.c

@@ -49,10 +49,10 @@ struct cred init_cred = {
 	.magic			= CRED_MAGIC,
 #endif
 	.securebits		= SECUREBITS_DEFAULT,
-	.cap_inheritable	= CAP_INIT_INH_SET,
+	.cap_inheritable	= CAP_EMPTY_SET,
 	.cap_permitted		= CAP_FULL_SET,
-	.cap_effective		= CAP_INIT_EFF_SET,
-	.cap_bset		= CAP_INIT_BSET,
+	.cap_effective		= CAP_FULL_SET,
+	.cap_bset		= CAP_FULL_SET,
 	.user			= INIT_USER,
 	.user_ns		= &init_user_ns,
 	.group_info		= &init_groups,

kernel/kmod.c

@@ -25,6 +25,7 @@
 #include <linux/kmod.h>
 #include <linux/slab.h>
 #include <linux/completion.h>
+#include <linux/cred.h>
 #include <linux/file.h>
 #include <linux/fdtable.h>
 #include <linux/workqueue.h>
@@ -43,6 +44,13 @@ extern int max_threads;
 
 static struct workqueue_struct *khelper_wq;
 
+#define CAP_BSET	(void *)1
+#define CAP_PI		(void *)2
+
+static kernel_cap_t usermodehelper_bset = CAP_FULL_SET;
+static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET;
+static DEFINE_SPINLOCK(umh_sysctl_lock);
+
 #ifdef CONFIG_MODULES
 
 /*
@@ -132,6 +140,7 @@ EXPORT_SYMBOL(__request_module);
 static int ____call_usermodehelper(void *data)
 {
 	struct subprocess_info *sub_info = data;
+	struct cred *new;
 	int retval;
 
 	spin_lock_irq(&current->sighand->siglock);
@@ -153,6 +162,19 @@ static int ____call_usermodehelper(void *data)
 			goto fail;
 	}
 
+	retval = -ENOMEM;
+	new = prepare_kernel_cred(current);
+	if (!new)
+		goto fail;
+
+	spin_lock(&umh_sysctl_lock);
+	new->cap_bset = cap_intersect(usermodehelper_bset, new->cap_bset);
+	new->cap_inheritable = cap_intersect(usermodehelper_inheritable,
+					     new->cap_inheritable);
+	spin_unlock(&umh_sysctl_lock);
+
+	commit_creds(new);
+
 	retval = kernel_execve(sub_info->path,
 			       (const char *const *)sub_info->argv,
 			       (const char *const *)sub_info->envp);
@@ -420,6 +442,84 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
 }
 EXPORT_SYMBOL(call_usermodehelper_exec);
 
+static int proc_cap_handler(struct ctl_table *table, int write,
+			 void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table t;
+	unsigned long cap_array[_KERNEL_CAPABILITY_U32S];
+	kernel_cap_t new_cap;
+	int err, i;
+
+	if (write && (!capable(CAP_SETPCAP) ||
+		      !capable(CAP_SYS_MODULE)))
+		return -EPERM;
+
+	/*
+	 * convert from the global kernel_cap_t to the ulong array to print to
+	 * userspace if this is a read.
+	 */
+	spin_lock(&umh_sysctl_lock);
+	for (i = 0; i < _KERNEL_CAPABILITY_U32S; i++)  {
+		if (table->data == CAP_BSET)
+			cap_array[i] = usermodehelper_bset.cap[i];
+		else if (table->data == CAP_PI)
+			cap_array[i] = usermodehelper_inheritable.cap[i];
+		else
+			BUG();
+	}
+	spin_unlock(&umh_sysctl_lock);
+
+	t = *table;
+	t.data = &cap_array;
+
+	/*
+	 * actually read or write and array of ulongs from userspace.  Remember
+	 * these are least significant 32 bits first
+	 */
+	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
+	if (err < 0)
+		return err;
+
+	/*
+	 * convert from the sysctl array of ulongs to the kernel_cap_t
+	 * internal representation
+	 */
+	for (i = 0; i < _KERNEL_CAPABILITY_U32S; i++)
+		new_cap.cap[i] = cap_array[i];
+
+	/*
+	 * Drop everything not in the new_cap (but don't add things)
+	 */
+	spin_lock(&umh_sysctl_lock);
+	if (write) {
+		if (table->data == CAP_BSET)
+			usermodehelper_bset = cap_intersect(usermodehelper_bset, new_cap);
+		if (table->data == CAP_PI)
+			usermodehelper_inheritable = cap_intersect(usermodehelper_inheritable, new_cap);
+	}
+	spin_unlock(&umh_sysctl_lock);
+
+	return 0;
+}
+
+struct ctl_table usermodehelper_table[] = {
+	{
+		.procname	= "bset",
+		.data		= CAP_BSET,
+		.maxlen		= _KERNEL_CAPABILITY_U32S * sizeof(unsigned long),
+		.mode		= 0600,
+		.proc_handler	= proc_cap_handler,
+	},
+	{
+		.procname	= "inheritable",
+		.data		= CAP_PI,
+		.maxlen		= _KERNEL_CAPABILITY_U32S * sizeof(unsigned long),
+		.mode		= 0600,
+		.proc_handler	= proc_cap_handler,
+	},
+	{ }
+};
+
 void __init usermodehelper_init(void)
 {
 	khelper_wq = create_singlethread_workqueue("khelper");

kernel/sysctl.c

@@ -56,6 +56,7 @@
 #include <linux/kprobes.h>
 #include <linux/pipe_fs_i.h>
 #include <linux/oom.h>
+#include <linux/kmod.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -615,6 +616,11 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0555,
 		.child		= random_table,
 	},
+	{
+		.procname	= "usermodehelper",
+		.mode		= 0555,
+		.child		= usermodehelper_table,
+	},
 	{
 		.procname	= "overflowuid",
 		.data		= &overflowuid,

net/dns_resolver/dns_key.c

@@ -212,10 +212,12 @@ static void dns_resolver_describe(const struct key *key, struct seq_file *m)
 	int err = key->type_data.x[0];
 
 	seq_puts(m, key->description);
-	if (err)
-		seq_printf(m, ": %d", err);
-	else
-		seq_printf(m, ": %u", key->datalen);
+	if (key_is_instantiated(key)) {
+		if (err)
+			seq_printf(m, ": %d", err);
+		else
+			seq_printf(m, ": %u", key->datalen);
+	}
 }
 
 /*

security/Kconfig

@@ -167,6 +167,7 @@ config INTEL_TXT
 config LSM_MMAP_MIN_ADDR
 	int "Low address space for LSM to protect from user allocation"
 	depends on SECURITY && SECURITY_SELINUX
+	default 32768 if ARM
 	default 65536
 	help
 	  This is the portion of low virtual memory which should be protected

security/commoncap.c

@@ -529,15 +529,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
 	new->suid = new->fsuid = new->euid;
 	new->sgid = new->fsgid = new->egid;
 
-	/* For init, we want to retain the capabilities set in the initial
-	 * task.  Thus we skip the usual capability rules
-	 */
-	if (!is_global_init(current)) {
-		if (effective)
-			new->cap_effective = new->cap_permitted;
-		else
-			cap_clear(new->cap_effective);
-	}
+	if (effective)
+		new->cap_effective = new->cap_permitted;
+	else
+		cap_clear(new->cap_effective);
 	bprm->cap_effective = effective;
 
 	/*

security/keys/internal.h

@@ -109,11 +109,13 @@ extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 				    const struct cred *cred,
 				    struct key_type *type,
 				    const void *description,
-				    key_match_func_t match);
+				    key_match_func_t match,
+				    bool no_state_check);
 
 extern key_ref_t search_my_process_keyrings(struct key_type *type,
 					    const void *description,
 					    key_match_func_t match,
+					    bool no_state_check,
 					    const struct cred *cred);
 extern key_ref_t search_process_keyrings(struct key_type *type,
 					 const void *description,

security/keys/keyctl.c

@@ -206,8 +206,14 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
 		goto error5;
 	}
 
+	/* wait for the key to finish being constructed */
+	ret = wait_for_key_construction(key, 1);
+	if (ret < 0)
+		goto error6;
+
 	ret = key->serial;
 
+error6:
  	key_put(key);
 error5:
 	key_type_put(ktype);