1 files changed, 107 insertions, 44 deletions

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index ee6f7e237f2e..5149ff4fd50d 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -8,6 +8,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/file.h>
+#include <linux/binfmts.h>
 #include <linux/fs.h>
 #include <linux/xattr.h>
 #include <linux/magic.h>
@@ -70,22 +71,21 @@ bool is_ima_appraise_enabled(void)
  *
  * Return 1 to appraise or hash
  */
-int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
+int ima_must_appraise(struct mnt_idmap *idmap, struct inode *inode,
 		      int mask, enum ima_hooks func)
 {
-	u32 secid;
+	struct lsm_prop prop;
 
 	if (!ima_appraise)
 		return 0;
 
-	security_current_getsecid_subj(&secid);
-	return ima_match_policy(mnt_userns, inode, current_cred(), secid,
+	security_current_getlsmprop_subj(&prop);
+	return ima_match_policy(idmap, inode, current_cred(), &prop,
 				func, mask, IMA_APPRAISE | IMA_HASH, NULL,
 				NULL, NULL, NULL);
 }
 
-static int ima_fix_xattr(struct dentry *dentry,
-			 struct integrity_iint_cache *iint)
+static int ima_fix_xattr(struct dentry *dentry, struct ima_iint_cache *iint)
 {
 	int rc, offset;
 	u8 algo = iint->ima_hash->algo;
@@ -98,7 +98,7 @@ static int ima_fix_xattr(struct dentry *dentry,
 		iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG;
 		iint->ima_hash->xattr.ng.algo = algo;
 	}
-	rc = __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_IMA,
+	rc = __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_IMA,
 				   &iint->ima_hash->xattr.data[offset],
 				   (sizeof(iint->ima_hash->xattr) - offset) +
 				   iint->ima_hash->length, 0);
@@ -106,11 +106,12 @@ static int ima_fix_xattr(struct dentry *dentry,
 }
 
 /* Return specific func appraised cached result */
-enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
+enum integrity_status ima_get_cache_status(struct ima_iint_cache *iint,
 					   enum ima_hooks func)
 {
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		return iint->ima_mmap_status;
 	case BPRM_CHECK:
 		return iint->ima_bprm_status;
@@ -125,12 +126,13 @@ enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 	}
 }
 
-static void ima_set_cache_status(struct integrity_iint_cache *iint,
+static void ima_set_cache_status(struct ima_iint_cache *iint,
 				 enum ima_hooks func,
 				 enum integrity_status status)
 {
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		iint->ima_mmap_status = status;
 		break;
 	case BPRM_CHECK:
@@ -150,11 +152,11 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint,
 	}
 }
 
-static void ima_cache_flags(struct integrity_iint_cache *iint,
-			     enum ima_hooks func)
+static void ima_cache_flags(struct ima_iint_cache *iint, enum ima_hooks func)
 {
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED);
 		break;
 	case BPRM_CHECK:
@@ -225,7 +227,7 @@ int ima_read_xattr(struct dentry *dentry,
 {
 	int ret;
 
-	ret = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_IMA,
+	ret = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, XATTR_NAME_IMA,
 				 (char **)xattr_value, xattr_len, GFP_NOFS);
 	if (ret == -EOPNOTSUPP)
 		ret = 0;
@@ -273,7 +275,7 @@ static int calc_file_id_hash(enum evm_ima_xattr_type type,
  *
  * Return 0 on success, error code otherwise.
  */
-static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
+static int xattr_verify(enum ima_hooks func, struct ima_iint_cache *iint,
 			struct evm_ima_xattr_data *xattr_value, int xattr_len,
 			enum integrity_status *status, const char **cause)
 {
@@ -377,7 +379,9 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
 		}
 
 		rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo,
-				       iint->ima_hash->digest, &hash.hdr);
+				       iint->ima_hash->digest,
+				       container_of(&hash.hdr,
+					       struct ima_digest_data, hdr));
 		if (rc) {
 			*cause = "sigv3-hashing-error";
 			*status = INTEGRITY_FAIL;
@@ -440,7 +444,7 @@ static int modsig_verify(enum ima_hooks func, const struct modsig *modsig,
  *
  * Returns -EPERM if the hash is blacklisted.
  */
-int ima_check_blacklist(struct integrity_iint_cache *iint,
+int ima_check_blacklist(struct ima_iint_cache *iint,
 			const struct modsig *modsig, int pcr)
 {
 	enum hash_algo hash_algo;
@@ -455,15 +459,28 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
 		ima_get_modsig_digest(modsig, &hash_algo, &digest, &digestsize);
 
 		rc = is_binary_blacklisted(digest, digestsize);
-		if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
-			process_buffer_measurement(&init_user_ns, NULL, digest, digestsize,
-						   "blacklisted-hash", NONE,
-						   pcr, NULL, false, NULL, 0);
-	}
+	} else if (iint->flags & IMA_DIGSIG_REQUIRED && iint->ima_hash)
+		rc = is_binary_blacklisted(iint->ima_hash->digest, iint->ima_hash->length);
+
+	if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
+		process_buffer_measurement(&nop_mnt_idmap, NULL, digest, digestsize,
+					   "blacklisted-hash", NONE,
+					   pcr, NULL, false, NULL, 0);
 
 	return rc;
 }
 
+static bool is_bprm_creds_for_exec(enum ima_hooks func, struct file *file)
+{
+	struct linux_binprm *bprm;
+
+	if (func == BPRM_CHECK) {
+		bprm = container_of(&file, struct linux_binprm, file);
+		return bprm->is_check;
+	}
+	return false;
+}
+
 /*
  * ima_appraise_measurement - appraise file measurement
  *
@@ -472,13 +489,13 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
  *
  * Return 0 on success, error code otherwise
  */
-int ima_appraise_measurement(enum ima_hooks func,
-			     struct integrity_iint_cache *iint,
+int ima_appraise_measurement(enum ima_hooks func, struct ima_iint_cache *iint,
 			     struct file *file, const unsigned char *filename,
 			     struct evm_ima_xattr_data *xattr_value,
 			     int xattr_len, const struct modsig *modsig)
 {
 	static const char op[] = "appraise_data";
+	int audit_msgno = AUDIT_INTEGRITY_DATA;
 	const char *cause = "unknown";
 	struct dentry *dentry = file_dentry(file);
 	struct inode *inode = d_backing_inode(dentry);
@@ -490,6 +507,16 @@ int ima_appraise_measurement(enum ima_hooks func,
 	if (!(inode->i_opflags & IOP_XATTR) && !try_modsig)
 		return INTEGRITY_UNKNOWN;
 
+	/*
+	 * Unlike any of the other LSM hooks where the kernel enforces file
+	 * integrity, enforcing file integrity for the bprm_creds_for_exec()
+	 * LSM hook with the AT_EXECVE_CHECK flag is left up to the discretion
+	 * of the script interpreter(userspace). Differentiate kernel and
+	 * userspace enforced integrity audit messages.
+	 */
+	if (is_bprm_creds_for_exec(func, file))
+		audit_msgno = AUDIT_INTEGRITY_USERSPACE;
+
 	/* If reading the xattr failed and there's no modsig, error out. */
 	if (rc <= 0 && !try_modsig) {
 		if (rc && rc != -ENODATA)
@@ -515,7 +542,7 @@ int ima_appraise_measurement(enum ima_hooks func,
 	}
 
 	status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value,
-				 rc < 0 ? 0 : rc, iint);
+				 rc < 0 ? 0 : rc);
 	switch (status) {
 	case INTEGRITY_PASS:
 	case INTEGRITY_PASS_IMMUTABLE:
@@ -565,7 +592,7 @@ out:
 	     (iint->flags & IMA_FAIL_UNVERIFIABLE_SIGS))) {
 		status = INTEGRITY_FAIL;
 		cause = "unverifiable-signature";
-		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+		integrity_audit_msg(audit_msgno, inode, filename,
 				    op, cause, rc, 0);
 	} else if (status != INTEGRITY_PASS) {
 		/* Fix mode, but don't replace file signatures. */
@@ -585,7 +612,7 @@ out:
 			status = INTEGRITY_PASS;
 		}
 
-		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+		integrity_audit_msg(audit_msgno, inode, filename,
 				    op, cause, rc, 0);
 	} else {
 		ima_cache_flags(iint, func);
@@ -598,7 +625,7 @@ out:
 /*
  * ima_update_xattr - update 'security.ima' hash value
  */
-void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
+void ima_update_xattr(struct ima_iint_cache *iint, struct file *file)
 {
 	struct dentry *dentry = file_dentry(file);
 	int rc = 0;
@@ -622,27 +649,28 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
 
 /**
  * ima_inode_post_setattr - reflect file metadata changes
- * @mnt_userns:	user namespace of the mount the inode was found from
+ * @idmap:  idmap of the mount the inode was found from
  * @dentry: pointer to the affected dentry
+ * @ia_valid: for the UID and GID status
  *
  * Changes to a dentry's metadata might result in needing to appraise.
  *
  * This function is called from notify_change(), which expects the caller
  * to lock the inode's i_mutex.
  */
-void ima_inode_post_setattr(struct user_namespace *mnt_userns,
-			    struct dentry *dentry)
+static void ima_inode_post_setattr(struct mnt_idmap *idmap,
+				   struct dentry *dentry, int ia_valid)
 {
 	struct inode *inode = d_backing_inode(dentry);
-	struct integrity_iint_cache *iint;
+	struct ima_iint_cache *iint;
 	int action;
 
 	if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode)
 	    || !(inode->i_opflags & IOP_XATTR))
 		return;
 
-	action = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, POST_SETATTR);
-	iint = integrity_iint_find(inode);
+	action = ima_must_appraise(idmap, inode, MAY_ACCESS, POST_SETATTR);
+	iint = ima_iint_find(inode);
 	if (iint) {
 		set_bit(IMA_CHANGE_ATTR, &iint->atomic_flags);
 		if (!action)
@@ -666,21 +694,30 @@ static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
 	return 0;
 }
 
+/*
+ * ima_reset_appraise_flags - reset ima_iint_cache flags
+ *
+ * @digsig: whether to clear/set IMA_DIGSIG flag, tristate values
+ *          0: clear IMA_DIGSIG
+ *          1: set IMA_DIGSIG
+ *         -1: don't change IMA_DIGSIG
+ *
+ */
 static void ima_reset_appraise_flags(struct inode *inode, int digsig)
 {
-	struct integrity_iint_cache *iint;
+	struct ima_iint_cache *iint;
 
 	if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode))
 		return;
 
-	iint = integrity_iint_find(inode);
+	iint = ima_iint_find(inode);
 	if (!iint)
 		return;
 	iint->measured_pcrs = 0;
 	set_bit(IMA_CHANGE_XATTR, &iint->atomic_flags);
-	if (digsig)
+	if (digsig == 1)
 		set_bit(IMA_DIGSIG, &iint->atomic_flags);
-	else
+	else if (digsig == 0)
 		clear_bit(IMA_DIGSIG, &iint->atomic_flags);
 }
 
@@ -744,8 +781,9 @@ static int validate_hash_algo(struct dentry *dentry,
 	return -EACCES;
 }
 
-int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
-		       const void *xattr_value, size_t xattr_value_len)
+static int ima_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
+			      const char *xattr_name, const void *xattr_value,
+			      size_t xattr_value_len, int flags)
 {
 	const struct evm_ima_xattr_data *xvalue = xattr_value;
 	int digsig = 0;
@@ -765,6 +803,8 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 		digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG);
 	} else if (!strcmp(xattr_name, XATTR_NAME_EVM) && xattr_value_len > 0) {
 		digsig = (xvalue->type == EVM_XATTR_PORTABLE_DIGSIG);
+	} else {
+		digsig = -1;
 	}
 	if (result == 1 || evm_revalidate_status(xattr_name)) {
 		ima_reset_appraise_flags(d_backing_inode(dentry), digsig);
@@ -774,24 +814,47 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 	return result;
 }
 
-int ima_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
-		      const char *acl_name, struct posix_acl *kacl)
+static int ima_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+			     const char *acl_name, struct posix_acl *kacl)
 {
 	if (evm_revalidate_status(acl_name))
-		ima_reset_appraise_flags(d_backing_inode(dentry), 0);
+		ima_reset_appraise_flags(d_backing_inode(dentry), -1);
 
 	return 0;
 }
 
-int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+static int ima_inode_removexattr(struct mnt_idmap *idmap, struct dentry *dentry,
+				 const char *xattr_name)
 {
-	int result;
+	int result, digsig = -1;
 
 	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
 	if (result == 1 || evm_revalidate_status(xattr_name)) {
-		ima_reset_appraise_flags(d_backing_inode(dentry), 0);
+		if (!strcmp(xattr_name, XATTR_NAME_IMA))
+			digsig = 0;
+		ima_reset_appraise_flags(d_backing_inode(dentry), digsig);
 		if (result == 1)
 			result = 0;
 	}
 	return result;
 }
+
+static int ima_inode_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+				const char *acl_name)
+{
+	return ima_inode_set_acl(idmap, dentry, acl_name, NULL);
+}
+
+static struct security_hook_list ima_appraise_hooks[] __ro_after_init = {
+	LSM_HOOK_INIT(inode_post_setattr, ima_inode_post_setattr),
+	LSM_HOOK_INIT(inode_setxattr, ima_inode_setxattr),
+	LSM_HOOK_INIT(inode_set_acl, ima_inode_set_acl),
+	LSM_HOOK_INIT(inode_removexattr, ima_inode_removexattr),
+	LSM_HOOK_INIT(inode_remove_acl, ima_inode_remove_acl),
+};
+
+void __init init_ima_appraise_lsm(const struct lsm_id *lsmid)
+{
+	security_add_hooks(ima_appraise_hooks, ARRAY_SIZE(ima_appraise_hooks),
+			   lsmid);
+}