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:
  SELinux: do not destroy the avc_cache_nodep
  KEYS: Have the garbage collector set its timer for live expired keys
  tpm-fixup-pcrs-sysfs-file-update
  creds_are_invalid() needs to be exported for use by modules:
  include/linux/cred.h: fix build

Fix trivial BUILD_BUG_ON-induced conflicts in drivers/char/tpm/tpm.c

5 files changed, 39 insertions, 26 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 32b957efa420..45d58002b06c 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -742,7 +742,7 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read);
  * the module usage count.
  */
 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
-#define EXTEND_PCR_SIZE 34
+#define EXTEND_PCR_RESULT_SIZE 34
 static struct tpm_input_header pcrextend_header = {
 	.tag = TPM_TAG_RQU_COMMAND,
 	.length = cpu_to_be32(34),
@@ -760,10 +760,9 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 		return -ENODEV;
 
 	cmd.header.in = pcrextend_header;
-	BUG_ON(be32_to_cpu(cmd.header.in.length) > EXTEND_PCR_SIZE);
 	cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 	memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
-	rc = transmit_cmd(chip, &cmd, cmd.header.in.length,
+	rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 			  "attempting extend a PCR value");
 
 	module_put(chip->dev->driver->owner);
diff --git a/include/linux/cred.h b/include/linux/cred.h
index fb371601a3b4..4e3387a89cb9 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -176,23 +176,7 @@ extern void __invalid_creds(const struct cred *, const char *, unsigned);
 extern void __validate_process_creds(struct task_struct *,
 				     const char *, unsigned);
 
-static inline bool creds_are_invalid(const struct cred *cred)
-{
-	if (cred->magic != CRED_MAGIC)
-		return true;
-	if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))
-		return true;
-#ifdef CONFIG_SECURITY_SELINUX
-	if (selinux_is_enabled()) {
-		if ((unsigned long) cred->security < PAGE_SIZE)
-			return true;
-		if ((*(u32 *)cred->security & 0xffffff00) ==
-		    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
-			return true;
-	}
-#endif
-	return false;
-}
+extern bool creds_are_invalid(const struct cred *cred);
 
 static inline void __validate_creds(const struct cred *cred,
 				    const char *file, unsigned line)
diff --git a/kernel/cred.c b/kernel/cred.c
index d7f7a01082eb..dd76cfe5f5b0 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -782,6 +782,25 @@ EXPORT_SYMBOL(set_create_files_as);
 
 #ifdef CONFIG_DEBUG_CREDENTIALS
 
+bool creds_are_invalid(const struct cred *cred)
+{
+	if (cred->magic != CRED_MAGIC)
+		return true;
+	if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))
+		return true;
+#ifdef CONFIG_SECURITY_SELINUX
+	if (selinux_is_enabled()) {
+		if ((unsigned long) cred->security < PAGE_SIZE)
+			return true;
+		if ((*(u32 *)cred->security & 0xffffff00) ==
+		    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
+			return true;
+	}
+#endif
+	return false;
+}
+EXPORT_SYMBOL(creds_are_invalid);
+
 /*
  * dump invalid credentials
  */
diff --git a/security/keys/gc.c b/security/keys/gc.c
index 485fc6233c38..4770be375ffe 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -169,9 +169,9 @@ static void key_garbage_collector(struct work_struct *work)
 
 	/* trawl through the keys looking for keyrings */
 	for (;;) {
-		if (key->expiry > now && key->expiry < new_timer) {
+		if (key->expiry > limit && key->expiry < new_timer) {
 			kdebug("will expire %x in %ld",
-			       key_serial(key), key->expiry - now);
+			       key_serial(key), key->expiry - limit);
 			new_timer = key->expiry;
 		}
 
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 1ed0f076aadc..b4b5da1c0a42 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -868,8 +868,19 @@ u32 avc_policy_seqno(void)
 
 void avc_disable(void)
 {
-	avc_flush();
-	synchronize_rcu();
-	if (avc_node_cachep)
-		kmem_cache_destroy(avc_node_cachep);
+	/*
+	 * If you are looking at this because you have realized that we are
+	 * not destroying the avc_node_cachep it might be easy to fix, but
+	 * I don't know the memory barrier semantics well enough to know.  It's
+	 * possible that some other task dereferenced security_ops when
+	 * it still pointed to selinux operations.  If that is the case it's
+	 * possible that it is about to use the avc and is about to need the
+	 * avc_node_cachep.  I know I could wrap the security.c security_ops call
+	 * in an rcu_lock, but seriously, it's not worth it.  Instead I just flush
+	 * the cache and get that memory back.
+	 */
+	if (avc_node_cachep) {
+		avc_flush();
+		/* kmem_cache_destroy(avc_node_cachep); */
+	}
 }