Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:
 "In this patchset, we finally get an SELinux update, with Paul Moore
  taking over as maintainer of that code.

  Also a significant update for the Keys subsystem, as well as
  maintenance updates to Smack, IMA, TPM, and Apparmor"

and since I wanted to know more about the updates to key handling,
here's the explanation from David Howells on that:

 "Okay.  There are a number of separate bits.  I'll go over the big bits
  and the odd important other bit, most of the smaller bits are just
  fixes and cleanups.  If you want the small bits accounting for, I can
  do that too.

   (1) Keyring capacity expansion.

        KEYS: Consolidate the concept of an 'index key' for key access
        KEYS: Introduce a search context structure
        KEYS: Search for auth-key by name rather than target key ID
        Add a generic associative array implementation.
        KEYS: Expand the capacity of a keyring

     Several of the patches are providing an expansion of the capacity of a
     keyring.  Currently, the maximum size of a keyring payload is one page.
     Subtract a small header and then divide up into pointers, that only gives
     you ~500 pointers on an x86_64 box.  However, since the NFS idmapper uses
     a keyring to store ID mapping data, that has proven to be insufficient to
     the cause.

     Whatever data structure I use to handle the keyring payload, it can only
     store pointers to keys, not the keys themselves because several keyrings
     may point to a single key.  This precludes inserting, say, and rb_node
     struct into the key struct for this purpose.

     I could make an rbtree of records such that each record has an rb_node
     and a key pointer, but that would use four words of space per key stored
     in the keyring.  It would, however, be able to use much existing code.

     I selected instead a non-rebalancing radix-tree type approach as that
     could have a better space-used/key-pointer ratio.  I could have used the
     radix tree implementation that we already have and insert keys into it by
     their serial numbers, but that means any sort of search must iterate over
     the whole radix tree.  Further, its nodes are a bit on the capacious side
     for what I want - especially given that key serial numbers are randomly
     allocated, thus leaving a lot of empty space in the tree.

     So what I have is an associative array that internally is a radix-tree
     with 16 pointers per node where the index key is constructed from the key
     type pointer and the key description.  This means that an exact lookup by
     type+description is very fast as this tells us how to navigate directly to
     the target key.

     I made the data structure general in lib/assoc_array.c as far as it is
     concerned, its index key is just a sequence of bits that leads to a
     pointer.  It's possible that someone else will be able to make use of it
     also.  FS-Cache might, for example.

   (2) Mark keys as 'trusted' and keyrings as 'trusted only'.

        KEYS: verify a certificate is signed by a 'trusted' key
        KEYS: Make the system 'trusted' keyring viewable by userspace
        KEYS: Add a 'trusted' flag and a 'trusted only' flag
        KEYS: Separate the kernel signature checking keyring from module signing

     These patches allow keys carrying asymmetric public keys to be marked as
     being 'trusted' and allow keyrings to be marked as only permitting the
     addition or linkage of trusted keys.

     Keys loaded from hardware during kernel boot or compiled into the kernel
     during build are marked as being trusted automatically.  New keys can be
     loaded at runtime with add_key().  They are checked against the system
     keyring contents and if their signatures can be validated with keys that
     are already marked trusted, then they are marked trusted also and can
     thus be added into the master keyring.

     Patches from Mimi Zohar make this usable with the IMA keyrings also.

   (3) Remove the date checks on the key used to validate a module signature.

        X.509: Remove certificate date checks

     It's not reasonable to reject a signature just because the key that it was
     generated with is no longer valid datewise - especially if the kernel
     hasn't yet managed to set the system clock when the first module is
     loaded - so just remove those checks.

   (4) Make it simpler to deal with additional X.509 being loaded into the kernel.

        KEYS: Load *.x509 files into kernel keyring
        KEYS: Have make canonicalise the paths of the X.509 certs better to deduplicate

     The builder of the kernel now just places files with the extension ".x509"
     into the kernel source or build trees and they're concatenated by the
     kernel build and stuffed into the appropriate section.

   (5) Add support for userspace kerberos to use keyrings.

        KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches
        KEYS: Implement a big key type that can save to tmpfs

     Fedora went to, by default, storing kerberos tickets and tokens in tmpfs.
     We looked at storing it in keyrings instead as that confers certain
     advantages such as tickets being automatically deleted after a certain
     amount of time and the ability for the kernel to get at these tokens more
     easily.

     To make this work, two things were needed:

     (a) A way for the tickets to persist beyond the lifetime of all a user's
         sessions so that cron-driven processes can still use them.

         The problem is that a user's session keyrings are deleted when the
         session that spawned them logs out and the user's user keyring is
         deleted when the UID is deleted (typically when the last log out
         happens), so neither of these places is suitable.

         I've added a system keyring into which a 'persistent' keyring is
         created for each UID on request.  Each time a user requests their
         persistent keyring, the expiry time on it is set anew.  If the user
         doesn't ask for it for, say, three days, the keyring is automatically
         expired and garbage collected using the existing gc.  All the kerberos
         tokens it held are then also gc'd.

     (b) A key type that can hold really big tickets (up to 1MB in size).

         The problem is that Active Directory can return huge tickets with lots
         of auxiliary data attached.  We don't, however, want to eat up huge
         tracts of unswappable kernel space for this, so if the ticket is
         greater than a certain size, we create a swappable shmem file and dump
         the contents in there and just live with the fact we then have an
         inode and a dentry overhead.  If the ticket is smaller than that, we
         slap it in a kmalloc()'d buffer"

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (121 commits)
  KEYS: Fix keyring content gc scanner
  KEYS: Fix error handling in big_key instantiation
  KEYS: Fix UID check in keyctl_get_persistent()
  KEYS: The RSA public key algorithm needs to select MPILIB
  ima: define '_ima' as a builtin 'trusted' keyring
  ima: extend the measurement list to include the file signature
  kernel/system_certificate.S: use real contents instead of macro GLOBAL()
  KEYS: fix error return code in big_key_instantiate()
  KEYS: Fix keyring quota misaccounting on key replacement and unlink
  KEYS: Fix a race between negating a key and reading the error set
  KEYS: Make BIG_KEYS boolean
  apparmor: remove the "task" arg from may_change_ptraced_domain()
  apparmor: remove parent task info from audit logging
  apparmor: remove tsk field from the apparmor_audit_struct
  apparmor: fix capability to not use the current task, during reporting
  Smack: Ptrace access check mode
  ima: provide hash algo info in the xattr
  ima: enable support for larger default filedata hash algorithms
  ima: define kernel parameter 'ima_template=' to change configured default
  ima: add Kconfig default measurement list template
  ...

1 files changed, 94 insertions, 52 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c540795fb3f2..794c3ca49eac 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -95,7 +95,9 @@
 #include "audit.h"
 #include "avc_ss.h"
 
-#define NUM_SEL_MNT_OPTS 5
+#define SB_TYPE_FMT "%s%s%s"
+#define SB_SUBTYPE(sb) (sb->s_subtype && sb->s_subtype[0])
+#define SB_TYPE_ARGS(sb) sb->s_type->name, SB_SUBTYPE(sb) ? "." : "", SB_SUBTYPE(sb) ? sb->s_subtype : ""
 
 extern struct security_operations *security_ops;
 
@@ -139,12 +141,28 @@ static struct kmem_cache *sel_inode_cache;
  * This function checks the SECMARK reference counter to see if any SECMARK
  * targets are currently configured, if the reference counter is greater than
  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
- * enabled, false (0) if SECMARK is disabled.
+ * enabled, false (0) if SECMARK is disabled.  If the always_check_network
+ * policy capability is enabled, SECMARK is always considered enabled.
  *
  */
 static int selinux_secmark_enabled(void)
 {
-        return (atomic_read(&selinux_secmark_refcount) > 0);
+        return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount));
+}
+
+/**
+ * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
+ *
+ * Description:
+ * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
+ * (1) if any are enabled or false (0) if neither are enabled.  If the
+ * always_check_network policy capability is enabled, peer labeling
+ * is always considered enabled.
+ *
+ */
+static int selinux_peerlbl_enabled(void)
+{
+        return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled());
 }
 
 /*
@@ -309,8 +327,11 @@ enum {
         Opt_defcontext = 3,
         Opt_rootcontext = 4,
         Opt_labelsupport = 5,
+        Opt_nextmntopt = 6,
 };
 
+#define NUM_SEL_MNT_OPTS        (Opt_nextmntopt - 1)
+
 static const match_table_t tokens = {
         {Opt_context, CONTEXT_STR "%s"},
         {Opt_fscontext, FSCONTEXT_STR "%s"},
@@ -355,6 +376,29 @@ static int may_context_mount_inode_relabel(u32 sid,
         return rc;
 }
 
+static int selinux_is_sblabel_mnt(struct super_block *sb)
+{
+        struct superblock_security_struct *sbsec = sb->s_security;
+
+        if (sbsec->behavior == SECURITY_FS_USE_XATTR ||
+            sbsec->behavior == SECURITY_FS_USE_TRANS ||
+            sbsec->behavior == SECURITY_FS_USE_TASK)
+                return 1;
+
+        /* Special handling for sysfs. Is genfs but also has setxattr handler*/
+        if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
+                return 1;
+
+        /*
+         * Special handling for rootfs. Is genfs but supports
+         * setting SELinux context on in-core inodes.
+         */
+        if (strncmp(sb->s_type->name, "rootfs", sizeof("rootfs")) == 0)
+                return 1;
+
+        return 0;
+}
+
 static int sb_finish_set_opts(struct super_block *sb)
 {
         struct superblock_security_struct *sbsec = sb->s_security;
@@ -369,8 +413,8 @@ static int sb_finish_set_opts(struct super_block *sb)
                    the first boot of the SELinux kernel before we have
                    assigned xattr values to the filesystem. */
                 if (!root_inode->i_op->getxattr) {
-                        printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
-                               "xattr support\n", sb->s_id, sb->s_type->name);
+                        printk(KERN_WARNING "SELinux: (dev %s, type "SB_TYPE_FMT") has no "
+                               "xattr support\n", sb->s_id, SB_TYPE_ARGS(sb));
                         rc = -EOPNOTSUPP;
                         goto out;
                 }
@@ -378,35 +422,27 @@ static int sb_finish_set_opts(struct super_block *sb)
                 if (rc < 0 && rc != -ENODATA) {
                         if (rc == -EOPNOTSUPP)
                                 printk(KERN_WARNING "SELinux: (dev %s, type "
-                                       "%s) has no security xattr handler\n",
-                                       sb->s_id, sb->s_type->name);
+                                       SB_TYPE_FMT") has no security xattr handler\n",
+                                       sb->s_id, SB_TYPE_ARGS(sb));
                         else
                                 printk(KERN_WARNING "SELinux: (dev %s, type "
-                                       "%s) getxattr errno %d\n", sb->s_id,
-                                       sb->s_type->name, -rc);
+                                       SB_TYPE_FMT") getxattr errno %d\n", sb->s_id,
+                                       SB_TYPE_ARGS(sb), -rc);
                         goto out;
                 }
         }
 
-        sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
-
         if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
-                printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
-                       sb->s_id, sb->s_type->name);
+                printk(KERN_ERR "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), unknown behavior\n",
+                       sb->s_id, SB_TYPE_ARGS(sb));
         else
-                printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
-                       sb->s_id, sb->s_type->name,
+                printk(KERN_DEBUG "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), %s\n",
+                       sb->s_id, SB_TYPE_ARGS(sb),
                        labeling_behaviors[sbsec->behavior-1]);
 
-        if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
-            sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
-            sbsec->behavior == SECURITY_FS_USE_NONE ||
-            sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
-                sbsec->flags &= ~SE_SBLABELSUPP;
-
-        /* Special handling for sysfs. Is genfs but also has setxattr handler*/
-        if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
-                sbsec->flags |= SE_SBLABELSUPP;
+        sbsec->flags |= SE_SBINITIALIZED;
+        if (selinux_is_sblabel_mnt(sb))
+                sbsec->flags |= SBLABEL_MNT;
 
         /* Initialize the root inode. */
         rc = inode_doinit_with_dentry(root_inode, root);
@@ -460,15 +496,18 @@ static int selinux_get_mnt_opts(const struct super_block *sb,
         if (!ss_initialized)
                 return -EINVAL;
 
+        /* make sure we always check enough bits to cover the mask */
+        BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));
+
         tmp = sbsec->flags & SE_MNTMASK;
         /* count the number of mount options for this sb */
-        for (i = 0; i < 8; i++) {
+        for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
                 if (tmp & 0x01)
                         opts->num_mnt_opts++;
                 tmp >>= 1;
         }
         /* Check if the Label support flag is set */
-        if (sbsec->flags & SE_SBLABELSUPP)
+        if (sbsec->flags & SBLABEL_MNT)
                 opts->num_mnt_opts++;
 
         opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
@@ -515,9 +554,9 @@ static int selinux_get_mnt_opts(const struct super_block *sb,
                 opts->mnt_opts[i] = context;
                 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
         }
-        if (sbsec->flags & SE_SBLABELSUPP) {
+        if (sbsec->flags & SBLABEL_MNT) {
                 opts->mnt_opts[i] = NULL;
-                opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
+                opts->mnt_opts_flags[i++] = SBLABEL_MNT;
         }
 
         BUG_ON(i != opts->num_mnt_opts);
@@ -561,7 +600,6 @@ static int selinux_set_mnt_opts(struct super_block *sb,
         const struct cred *cred = current_cred();
         int rc = 0, i;
         struct superblock_security_struct *sbsec = sb->s_security;
-        const char *name = sb->s_type->name;
         struct inode *inode = sbsec->sb->s_root->d_inode;
         struct inode_security_struct *root_isec = inode->i_security;
         u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
@@ -614,14 +652,14 @@ static int selinux_set_mnt_opts(struct super_block *sb,
         for (i = 0; i < num_opts; i++) {
                 u32 sid;
 
-                if (flags[i] == SE_SBLABELSUPP)
+                if (flags[i] == SBLABEL_MNT)
                         continue;
                 rc = security_context_to_sid(mount_options[i],
                                              strlen(mount_options[i]), &sid);
                 if (rc) {
                         printk(KERN_WARNING "SELinux: security_context_to_sid"
-                               "(%s) failed for (dev %s, type %s) errno=%d\n",
-                               mount_options[i], sb->s_id, name, rc);
+                               "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n",
+                               mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc);
                         goto out;
                 }
                 switch (flags[i]) {
@@ -685,9 +723,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
                  * Determine the labeling behavior to use for this
                  * filesystem type.
                  */
-                rc = security_fs_use((sbsec->flags & SE_SBPROC) ?
-                                        "proc" : sb->s_type->name,
-                                        &sbsec->behavior, &sbsec->sid);
+                rc = security_fs_use(sb);
                 if (rc) {
                         printk(KERN_WARNING
                                 "%s: security_fs_use(%s) returned %d\n",
@@ -770,7 +806,8 @@ out:
 out_double_mount:
         rc = -EINVAL;
         printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
-               "security settings for (dev %s, type %s)\n", sb->s_id, name);
+               "security settings for (dev %s, type "SB_TYPE_FMT")\n", sb->s_id,
+               SB_TYPE_ARGS(sb));
         goto out;
 }
 
@@ -1037,7 +1074,7 @@ static void selinux_write_opts(struct seq_file *m,
                 case DEFCONTEXT_MNT:
                         prefix = DEFCONTEXT_STR;
                         break;
-                case SE_SBLABELSUPP:
+                case SBLABEL_MNT:
                         seq_putc(m, ',');
                         seq_puts(m, LABELSUPP_STR);
                         continue;
@@ -1649,7 +1686,7 @@ static int may_create(struct inode *dir,
         if (rc)
                 return rc;
 
-        if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
+        if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
                 rc = security_transition_sid(sid, dsec->sid, tclass,
                                              &dentry->d_name, &newsid);
                 if (rc)
@@ -2437,14 +2474,14 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
                 u32 sid;
                 size_t len;
 
-                if (flags[i] == SE_SBLABELSUPP)
+                if (flags[i] == SBLABEL_MNT)
                         continue;
                 len = strlen(mount_options[i]);
                 rc = security_context_to_sid(mount_options[i], len, &sid);
                 if (rc) {
                         printk(KERN_WARNING "SELinux: security_context_to_sid"
-                               "(%s) failed for (dev %s, type %s) errno=%d\n",
-                               mount_options[i], sb->s_id, sb->s_type->name, rc);
+                               "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n",
+                               mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc);
                         goto out_free_opts;
                 }
                 rc = -EINVAL;
@@ -2482,8 +2519,8 @@ out_free_secdata:
         return rc;
 out_bad_option:
         printk(KERN_WARNING "SELinux: unable to change security options "
-               "during remount (dev %s, type=%s)\n", sb->s_id,
-               sb->s_type->name);
+               "during remount (dev %s, type "SB_TYPE_FMT")\n", sb->s_id,
+               SB_TYPE_ARGS(sb));
         goto out_free_opts;
 }
 
@@ -2606,7 +2643,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
         if ((sbsec->flags & SE_SBINITIALIZED) &&
             (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
                 newsid = sbsec->mntpoint_sid;
-        else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
+        else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
                 rc = security_transition_sid(sid, dsec->sid,
                                              inode_mode_to_security_class(inode->i_mode),
                                              qstr, &newsid);
@@ -2628,7 +2665,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
                 isec->initialized = 1;
         }
 
-        if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
+        if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
                 return -EOPNOTSUPP;
 
         if (name)
@@ -2830,7 +2867,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
                 return selinux_inode_setotherxattr(dentry, name);
 
         sbsec = inode->i_sb->s_security;
-        if (!(sbsec->flags & SE_SBLABELSUPP))
+        if (!(sbsec->flags & SBLABEL_MNT))
                 return -EOPNOTSUPP;
 
         if (!inode_owner_or_capable(inode))
@@ -3791,8 +3828,12 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
         u32 nlbl_sid;
         u32 nlbl_type;
 
-        selinux_skb_xfrm_sid(skb, &xfrm_sid);
-        selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
+        err = selinux_skb_xfrm_sid(skb, &xfrm_sid);
+        if (unlikely(err))
+                return -EACCES;
+        err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
+        if (unlikely(err))
+                return -EACCES;
 
         err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
         if (unlikely(err)) {
@@ -4246,7 +4287,7 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
                 return selinux_sock_rcv_skb_compat(sk, skb, family);
 
         secmark_active = selinux_secmark_enabled();
-        peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
+        peerlbl_active = selinux_peerlbl_enabled();
         if (!secmark_active && !peerlbl_active)
                 return 0;
 
@@ -4628,7 +4669,7 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
 
         secmark_active = selinux_secmark_enabled();
         netlbl_active = netlbl_enabled();
-        peerlbl_active = netlbl_active || selinux_xfrm_enabled();
+        peerlbl_active = selinux_peerlbl_enabled();
         if (!secmark_active && !peerlbl_active)
                 return NF_ACCEPT;
 
@@ -4780,7 +4821,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
                 return NF_ACCEPT;
 #endif
         secmark_active = selinux_secmark_enabled();
-        peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
+        peerlbl_active = selinux_peerlbl_enabled();
         if (!secmark_active && !peerlbl_active)
                 return NF_ACCEPT;
 
@@ -5784,7 +5825,8 @@ static struct security_operations selinux_ops = {
         .xfrm_policy_clone_security =   selinux_xfrm_policy_clone,
         .xfrm_policy_free_security =    selinux_xfrm_policy_free,
         .xfrm_policy_delete_security =  selinux_xfrm_policy_delete,
-        .xfrm_state_alloc_security =    selinux_xfrm_state_alloc,
+        .xfrm_state_alloc =             selinux_xfrm_state_alloc,
+        .xfrm_state_alloc_acquire =     selinux_xfrm_state_alloc_acquire,
         .xfrm_state_free_security =     selinux_xfrm_state_free,
         .xfrm_state_delete_security =   selinux_xfrm_state_delete,
         .xfrm_policy_lookup =           selinux_xfrm_policy_lookup,