1 files changed, 95 insertions, 25 deletions

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 2d4becab891..d3113d4aaa3 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -15,6 +15,7 @@
 #include <linux/magic.h>
 #include <linux/ima.h>
 #include <linux/evm.h>
+#include <crypto/hash_info.h>
 
 #include "ima.h"
 
@@ -43,19 +44,31 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
 }
 
 static int ima_fix_xattr(struct dentry *dentry,
-			  struct integrity_iint_cache *iint)
+			 struct integrity_iint_cache *iint)
 {
-	iint->ima_xattr.type = IMA_XATTR_DIGEST;
-	return __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
-				     (u8 *)&iint->ima_xattr,
-				      sizeof(iint->ima_xattr), 0);
+	int rc, offset;
+	u8 algo = iint->ima_hash->algo;
+
+	if (algo <= HASH_ALGO_SHA1) {
+		offset = 1;
+		iint->ima_hash->xattr.sha1.type = IMA_XATTR_DIGEST;
+	} else {
+		offset = 0;
+		iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG;
+		iint->ima_hash->xattr.ng.algo = algo;
+	}
+	rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
+				   &iint->ima_hash->xattr.data[offset],
+				   (sizeof(iint->ima_hash->xattr) - offset) +
+				   iint->ima_hash->length, 0);
+	return rc;
 }
 
 /* Return specific func appraised cached result */
 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 					   int func)
 {
-	switch(func) {
+	switch (func) {
 	case MMAP_CHECK:
 		return iint->ima_mmap_status;
 	case BPRM_CHECK:
@@ -71,7 +84,7 @@ enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 static void ima_set_cache_status(struct integrity_iint_cache *iint,
 				 int func, enum integrity_status status)
 {
-	switch(func) {
+	switch (func) {
 	case MMAP_CHECK:
 		iint->ima_mmap_status = status;
 		break;
@@ -90,7 +103,7 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint,
 
 static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
 {
-	switch(func) {
+	switch (func) {
 	case MMAP_CHECK:
 		iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED);
 		break;
@@ -107,6 +120,50 @@ static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
 	}
 }
 
+void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
+		       struct ima_digest_data *hash)
+{
+	struct signature_v2_hdr *sig;
+
+	if (!xattr_value || xattr_len < 2)
+		return;
+
+	switch (xattr_value->type) {
+	case EVM_IMA_XATTR_DIGSIG:
+		sig = (typeof(sig))xattr_value;
+		if (sig->version != 2 || xattr_len <= sizeof(*sig))
+			return;
+		hash->algo = sig->hash_algo;
+		break;
+	case IMA_XATTR_DIGEST_NG:
+		hash->algo = xattr_value->digest[0];
+		break;
+	case IMA_XATTR_DIGEST:
+		/* this is for backward compatibility */
+		if (xattr_len == 21) {
+			unsigned int zero = 0;
+			if (!memcmp(&xattr_value->digest[16], &zero, 4))
+				hash->algo = HASH_ALGO_MD5;
+			else
+				hash->algo = HASH_ALGO_SHA1;
+		} else if (xattr_len == 17)
+			hash->algo = HASH_ALGO_MD5;
+		break;
+	}
+}
+
+int ima_read_xattr(struct dentry *dentry,
+		   struct evm_ima_xattr_data **xattr_value)
+{
+	struct inode *inode = dentry->d_inode;
+
+	if (!inode->i_op->getxattr)
+		return 0;
+
+	return vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value,
+				  0, GFP_NOFS);
+}
+
 /*
  * ima_appraise_measurement - appraise file measurement
  *
@@ -116,23 +173,22 @@ static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
  * Return 0 on success, error code otherwise
  */
 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
-			     struct file *file, const unsigned char *filename)
+			     struct file *file, const unsigned char *filename,
+			     struct evm_ima_xattr_data *xattr_value,
+			     int xattr_len)
 {
+	static const char op[] = "appraise_data";
+	char *cause = "unknown";
 	struct dentry *dentry = file->f_dentry;
 	struct inode *inode = dentry->d_inode;
-	struct evm_ima_xattr_data *xattr_value = NULL;
 	enum integrity_status status = INTEGRITY_UNKNOWN;
-	const char *op = "appraise_data";
-	char *cause = "unknown";
-	int rc;
+	int rc = xattr_len, hash_start = 0;
 
 	if (!ima_appraise)
 		return 0;
 	if (!inode->i_op->getxattr)
 		return INTEGRITY_UNKNOWN;
 
-	rc = vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)&xattr_value,
-				0, GFP_NOFS);
 	if (rc <= 0) {
 		if (rc && rc != -ENODATA)
 			goto out;
@@ -153,14 +209,25 @@ int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
 		goto out;
 	}
 	switch (xattr_value->type) {
+	case IMA_XATTR_DIGEST_NG:
+		/* first byte contains algorithm id */
+		hash_start = 1;
 	case IMA_XATTR_DIGEST:
 		if (iint->flags & IMA_DIGSIG_REQUIRED) {
 			cause = "IMA signature required";
 			status = INTEGRITY_FAIL;
 			break;
 		}
-		rc = memcmp(xattr_value->digest, iint->ima_xattr.digest,
-			    IMA_DIGEST_SIZE);
+		if (xattr_len - sizeof(xattr_value->type) - hash_start >=
+				iint->ima_hash->length)
+			/* xattr length may be longer. md5 hash in previous
+			   version occupied 20 bytes in xattr, instead of 16
+			 */
+			rc = memcmp(&xattr_value->digest[hash_start],
+				    iint->ima_hash->digest,
+				    iint->ima_hash->length);
+		else
+			rc = -EINVAL;
 		if (rc) {
 			cause = "invalid-hash";
 			status = INTEGRITY_FAIL;
@@ -171,9 +238,9 @@ int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
 	case EVM_IMA_XATTR_DIGSIG:
 		iint->flags |= IMA_DIGSIG;
 		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
-					     xattr_value->digest, rc - 1,
-					     iint->ima_xattr.digest,
-					     IMA_DIGEST_SIZE);
+					     (const char *)xattr_value, rc,
+					     iint->ima_hash->digest,
+					     iint->ima_hash->length);
 		if (rc == -EOPNOTSUPP) {
 			status = INTEGRITY_UNKNOWN;
 		} else if (rc) {
@@ -203,7 +270,6 @@ out:
 		ima_cache_flags(iint, func);
 	}
 	ima_set_cache_status(iint, func, status);
-	kfree(xattr_value);
 	return status;
 }
 
@@ -219,7 +285,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
 	if (iint->flags & IMA_DIGSIG)
 		return;
 
-	rc = ima_collect_measurement(iint, file);
+	rc = ima_collect_measurement(iint, file, NULL, NULL);
 	if (rc < 0)
 		return;
 
@@ -275,7 +341,7 @@ static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
 	return 0;
 }
 
-static void ima_reset_appraise_flags(struct inode *inode)
+static void ima_reset_appraise_flags(struct inode *inode, int digsig)
 {
 	struct integrity_iint_cache *iint;
 
@@ -287,18 +353,22 @@ static void ima_reset_appraise_flags(struct inode *inode)
 		return;
 
 	iint->flags &= ~IMA_DONE_MASK;
+	if (digsig)
+		iint->flags |= IMA_DIGSIG;
 	return;
 }
 
 int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 		       const void *xattr_value, size_t xattr_value_len)
 {
+	const struct evm_ima_xattr_data *xvalue = xattr_value;
 	int result;
 
 	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
 				   xattr_value_len);
 	if (result == 1) {
-		ima_reset_appraise_flags(dentry->d_inode);
+		ima_reset_appraise_flags(dentry->d_inode,
+			 (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0);
 		result = 0;
 	}
 	return result;
@@ -310,7 +380,7 @@ int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
 
 	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
 	if (result == 1) {
-		ima_reset_appraise_flags(dentry->d_inode);
+		ima_reset_appraise_flags(dentry->d_inode, 0);
 		result = 0;
 	}
 	return result;