Merge tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity subsystem updates from Mimi Zohar:

 - Limit the allowed hash algorithms when writing security.ima xattrs or
   verifying them, based on the IMA policy and the configured hash
   algorithms.

 - Return the calculated "critical data" measurement hash and size to
   avoid code duplication. (Preparatory change for a proposed LSM.)

 - and a single patch to address a compiler warning.

* tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  IMA: reject unknown hash algorithms in ima_get_hash_algo
  IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms
  IMA: introduce a new policy option func=SETXATTR_CHECK
  IMA: add a policy option to restrict xattr hash algorithms on appraisal
  IMA: add support to restrict the hash algorithms used for file appraisal
  IMA: block writes of the security.ima xattr with unsupported algorithms
  IMA: remove the dependency on CRYPTO_MD5
  ima: Add digest and digest_len params to the functions to measure a buffer
  ima: Return int in the functions to measure a buffer
  ima: Introduce ima_get_current_hash_algo()
  IMA: remove -Wmissing-prototypes warning

1 files changed, 14 insertions, 10 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index f0e448ed1f9f..be965a8715e4 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -46,8 +46,11 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 };
 /* current content of the policy */
 extern int ima_policy_flag;
 
+/* bitset of digests algorithms allowed in the setxattr hook */
+extern atomic_t ima_setxattr_allowed_hash_algorithms;
+
 /* set during initialization */
-extern int ima_hash_algo;
+extern int ima_hash_algo __ro_after_init;
 extern int ima_sha1_idx __ro_after_init;
 extern int ima_hash_algo_idx __ro_after_init;
 extern int ima_extra_slots __ro_after_init;
@@ -198,6 +201,7 @@ static inline unsigned int ima_hash_key(u8 *digest)
 	hook(KEXEC_CMDLINE, kexec_cmdline)		\
 	hook(KEY_CHECK, key)				\
 	hook(CRITICAL_DATA, critical_data)		\
+	hook(SETXATTR_CHECK, setxattr_check)		\
 	hook(MAX_CHECK, none)
 
 #define __ima_hook_enumify(ENUM, str)	ENUM,
@@ -254,7 +258,7 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
 		   const struct cred *cred, u32 secid, int mask,
 		   enum ima_hooks func, int *pcr,
 		   struct ima_template_desc **template_desc,
-		   const char *func_data);
+		   const char *func_data, unsigned int *allowed_algos);
 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 int ima_collect_measurement(struct integrity_iint_cache *iint,
 			    struct file *file, void *buf, loff_t size,
@@ -264,11 +268,11 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 			   struct evm_ima_xattr_data *xattr_value,
 			   int xattr_len, const struct modsig *modsig, int pcr,
 			   struct ima_template_desc *template_desc);
-void process_buffer_measurement(struct user_namespace *mnt_userns,
-				struct inode *inode, const void *buf, int size,
-				const char *eventname, enum ima_hooks func,
-				int pcr, const char *func_data,
-				bool buf_hash);
+int process_buffer_measurement(struct user_namespace *mnt_userns,
+			       struct inode *inode, const void *buf, int size,
+			       const char *eventname, enum ima_hooks func,
+			       int pcr, const char *func_data,
+			       bool buf_hash, u8 *digest, size_t digest_len);
 void ima_audit_measurement(struct integrity_iint_cache *iint,
 			   const unsigned char *filename);
 int ima_alloc_init_template(struct ima_event_data *event_data,
@@ -285,10 +289,10 @@ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
 		     const struct cred *cred, u32 secid, enum ima_hooks func,
 		     int mask, int flags, int *pcr,
 		     struct ima_template_desc **template_desc,
-		     const char *func_data);
+		     const char *func_data, unsigned int *allowed_algos);
 void ima_init_policy(void);
 void ima_update_policy(void);
-void ima_update_policy_flag(void);
+void ima_update_policy_flags(void);
 ssize_t ima_parse_add_rule(char *);
 void ima_delete_rules(void);
 int ima_check_policy(void);
@@ -319,7 +323,7 @@ int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 					   enum ima_hooks func);
-enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
+enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value,
 				 int xattr_len);
 int ima_read_xattr(struct dentry *dentry,
 		   struct evm_ima_xattr_data **xattr_value);