Merging upstream version 4.19.304.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 71 insertions, 19 deletions

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 6d1efe135..9c036a41e 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -474,7 +474,9 @@ void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name)
 
 /**
  * evm_inode_setattr - prevent updating an invalid EVM extended attribute
+ * @idmap: idmap of the mount
  * @dentry: pointer to the affected dentry
+ * @attr: iattr structure containing the new file attributes
  *
  * Permit update of file attributes when files have a valid EVM signature,
  * except in the case of them having an immutable portable signature.
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index 5a6810041..7c751c23e 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -46,12 +46,10 @@ static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
 		else if (inode > iint->inode)
 			n = n->rb_right;
 		else
-			break;
+			return iint;
 	}
-	if (!n)
-		return NULL;
 
-	return iint;
+	return NULL;
 }
 
 /*
@@ -71,9 +69,32 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
 	return iint;
 }
 
-static void iint_free(struct integrity_iint_cache *iint)
+#define IMA_MAX_NESTING (FILESYSTEM_MAX_STACK_DEPTH+1)
+
+/*
+ * It is not clear that IMA should be nested at all, but as long is it measures
+ * files both on overlayfs and on underlying fs, we need to annotate the iint
+ * mutex to avoid lockdep false positives related to IMA + overlayfs.
+ * See ovl_lockdep_annotate_inode_mutex_key() for more details.
+ */
+static inline void iint_lockdep_annotate(struct integrity_iint_cache *iint,
+					 struct inode *inode)
+{
+#ifdef CONFIG_LOCKDEP
+	static struct lock_class_key iint_mutex_key[IMA_MAX_NESTING];
+
+	int depth = inode->i_sb->s_stack_depth;
+
+	if (WARN_ON_ONCE(depth < 0 || depth >= IMA_MAX_NESTING))
+		depth = 0;
+
+	lockdep_set_class(&iint->mutex, &iint_mutex_key[depth]);
+#endif
+}
+
+static void iint_init_always(struct integrity_iint_cache *iint,
+			     struct inode *inode)
 {
-	kfree(iint->ima_hash);
 	iint->ima_hash = NULL;
 	iint->version = 0;
 	iint->flags = 0UL;
@@ -85,6 +106,14 @@ static void iint_free(struct integrity_iint_cache *iint)
 	iint->ima_creds_status = INTEGRITY_UNKNOWN;
 	iint->evm_status = INTEGRITY_UNKNOWN;
 	iint->measured_pcrs = 0;
+	mutex_init(&iint->mutex);
+	iint_lockdep_annotate(iint, inode);
+}
+
+static void iint_free(struct integrity_iint_cache *iint)
+{
+	kfree(iint->ima_hash);
+	mutex_destroy(&iint->mutex);
 	kmem_cache_free(iint_cache, iint);
 }
 
@@ -109,6 +138,8 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
 	if (!iint)
 		return NULL;
 
+	iint_init_always(iint, inode);
+
 	write_lock(&integrity_iint_lock);
 
 	p = &integrity_iint_tree.rb_node;
@@ -116,10 +147,15 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
 		parent = *p;
 		test_iint = rb_entry(parent, struct integrity_iint_cache,
 				     rb_node);
-		if (inode < test_iint->inode)
+		if (inode < test_iint->inode) {
 			p = &(*p)->rb_left;
-		else
+		} else if (inode > test_iint->inode) {
 			p = &(*p)->rb_right;
+		} else {
+			write_unlock(&integrity_iint_lock);
+			kmem_cache_free(iint_cache, iint);
+			return test_iint;
+		}
 	}
 
 	iint->inode = inode;
@@ -153,25 +189,18 @@ void integrity_inode_free(struct inode *inode)
 	iint_free(iint);
 }
 
-static void init_once(void *foo)
+static void iint_init_once(void *foo)
 {
 	struct integrity_iint_cache *iint = foo;
 
 	memset(iint, 0, sizeof(*iint));
-	iint->ima_file_status = INTEGRITY_UNKNOWN;
-	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
-	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
-	iint->ima_read_status = INTEGRITY_UNKNOWN;
-	iint->ima_creds_status = INTEGRITY_UNKNOWN;
-	iint->evm_status = INTEGRITY_UNKNOWN;
-	mutex_init(&iint->mutex);
 }
 
 static int __init integrity_iintcache_init(void)
 {
 	iint_cache =
 	    kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
-			      0, SLAB_PANIC, init_once);
+			      0, SLAB_PANIC, iint_init_once);
 	return 0;
 }
 security_initcall(integrity_iintcache_init);
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 3ec45028a..cd32fe331 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -7,7 +7,7 @@ config IMA
 	select CRYPTO_HMAC
 	select CRYPTO_SHA1
 	select CRYPTO_HASH_INFO
-	select TCG_TPM if HAS_IOMEM && !UML
+	select TCG_TPM if HAS_IOMEM
 	select TCG_TIS if TCG_TPM && X86
 	select TCG_CRB if TCG_TPM && ACPI
 	select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index a02c5acfd..377a6f7cd 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -201,6 +201,7 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 {
 	const char *audit_cause = "failed";
 	struct inode *inode = file_inode(file);
+	struct inode *real_inode = d_real_inode(file_dentry(file));
 	const char *filename = file->f_path.dentry->d_name.name;
 	int result = 0;
 	int length;
@@ -243,6 +244,10 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 	iint->ima_hash = tmpbuf;
 	memcpy(iint->ima_hash, &hash, length);
 	iint->version = i_version;
+	if (real_inode != inode) {
+		iint->real_ino = real_inode->i_ino;
+		iint->real_dev = real_inode->i_sb->s_dev;
+	}
 
 	/* Possibly temporary failure due to type of read (eg. O_DIRECT) */
 	if (!result)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index c85aab3bd..d9a33d433 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -29,6 +29,7 @@
 #include <linux/ima.h>
 #include <linux/iversion.h>
 #include <linux/fs.h>
+#include <linux/iversion.h>
 
 #include "ima.h"
 
@@ -170,7 +171,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 			       u32 secid, char *buf, loff_t size, int mask,
 			       enum ima_hooks func)
 {
-	struct inode *inode = file_inode(file);
+	struct inode *backing_inode, *inode = file_inode(file);
 	struct integrity_iint_cache *iint = NULL;
 	struct ima_template_desc *template_desc;
 	char *pathbuf = NULL;
@@ -242,6 +243,19 @@ static int process_measurement(struct file *file, const struct cred *cred,
 		iint->measured_pcrs = 0;
 	}
 
+	/* Detect and re-evaluate changes made to the backing file. */
+	backing_inode = d_real_inode(file_dentry(file));
+	if (backing_inode != inode &&
+	    (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) {
+		if (!IS_I_VERSION(backing_inode) ||
+		    backing_inode->i_sb->s_dev != iint->real_dev ||
+		    backing_inode->i_ino != iint->real_ino ||
+		    !inode_eq_iversion(backing_inode, iint->version)) {
+			iint->flags &= ~IMA_DONE_MASK;
+			iint->measured_pcrs = 0;
+		}
+	}
+
 	/* Determine if already appraised/measured based on bitmask
 	 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
 	 *  IMA_AUDIT, IMA_AUDITED)
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index e60473b13..b0264ba45 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -122,6 +122,8 @@ struct integrity_iint_cache {
 	unsigned long flags;
 	unsigned long measured_pcrs;
 	unsigned long atomic_flags;
+	unsigned long real_ino;
+	dev_t real_dev;
 	enum integrity_status ima_file_status:4;
 	enum integrity_status ima_mmap_status:4;
 	enum integrity_status ima_bprm_status:4;