Merge tag 'selinux-pr-20201012' of git://git.kernel.org/pub/scm/linux…

…/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "A decent number of SELinux patches for v5.10, twenty two in total. The
  highlights are listed below, but all of the patches pass our test
  suite and merge cleanly.

   - A number of changes to how the SELinux policy is loaded and managed
     inside the kernel with the goal of improving the atomicity of a
     SELinux policy load operation.

     These changes account for the bulk of the diffstat as well as the
     patch count. A special thanks to everyone who contributed patches
     and fixes for this work.

   - Convert the SELinux policy read-write lock to RCU.

   - A tracepoint was added for audited SELinux access control events;
     this should help provide a more unified backtrace across kernel and
     userspace.

   - Allow the removal of security.selinux xattrs when a SELinux policy
     is not loaded.

   - Enable policy capabilities in SELinux policies created with the
     scripts/selinux/mdp tool.

   - Provide some "no sooner than" dates for the SELinux checkreqprot
     sysfs deprecation"

* tag 'selinux-pr-20201012' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (22 commits)
  selinux: provide a "no sooner than" date for the checkreqprot removal
  selinux: Add helper functions to get and set checkreqprot
  selinux: access policycaps with READ_ONCE/WRITE_ONCE
  selinux: simplify away security_policydb_len()
  selinux: move policy mutex to selinux_state, use in lockdep checks
  selinux: fix error handling bugs in security_load_policy()
  selinux: convert policy read-write lock to RCU
  selinux: delete repeated words in comments
  selinux: add basic filtering for audit trace events
  selinux: add tracepoint on audited events
  selinux: Create new booleans and class dirs out of tree
  selinux: Standardize string literal usage for selinuxfs directory names
  selinux: Refactor selinuxfs directory populating functions
  selinux: Create function for selinuxfs directory cleanup
  selinux: permit removing security.selinux xattr before policy load
  selinux: fix memdup.cocci warnings
  selinux: avoid dereferencing the policy prior to initialization
  selinux: fix allocation failure check on newpolicy->sidtab
  selinux: refactor changing booleans
  selinux: move policy commit after updating selinuxfs
  ...

Documentation/ABI/obsolete/sysfs-selinux-checkreqprot

@@ -15,7 +15,7 @@ Description:
 	actual protection), and Android and Linux distributions have been
 	explicitly writing a "0" to /sys/fs/selinux/checkreqprot during
 	initialization for some time.  Support for setting checkreqprot to 1
-	will be	removed in a future kernel release, at which point the kernel
+	will be	removed no sooner than June 2021, at which point the kernel
 	will always cease using checkreqprot internally and will always
 	check the actual protections being applied upon mmap/mprotect calls.
 	The checkreqprot selinuxfs node will remain for backward compatibility

MAINTAINERS

@@ -15621,6 +15621,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git
 F:	Documentation/ABI/obsolete/sysfs-selinux-checkreqprot
 F:	Documentation/ABI/obsolete/sysfs-selinux-disable
 F:	Documentation/admin-guide/LSM/SELinux.rst
+F:	include/trace/events/avc.h
 F:	include/uapi/linux/selinux_netlink.h
 F:	scripts/selinux/
 F:	security/selinux/

include/trace/events/avc.h

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Authors:	Thiébaud Weksteen <tweek@google.com>
+ *		Peter Enderborg <Peter.Enderborg@sony.com>
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM avc
+
+#if !defined(_TRACE_SELINUX_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SELINUX_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(selinux_audited,
+
+	TP_PROTO(struct selinux_audit_data *sad,
+		char *scontext,
+		char *tcontext,
+		const char *tclass
+	),
+
+	TP_ARGS(sad, scontext, tcontext, tclass),
+
+	TP_STRUCT__entry(
+		__field(u32, requested)
+		__field(u32, denied)
+		__field(u32, audited)
+		__field(int, result)
+		__string(scontext, scontext)
+		__string(tcontext, tcontext)
+		__string(tclass, tclass)
+	),
+
+	TP_fast_assign(
+		__entry->requested	= sad->requested;
+		__entry->denied		= sad->denied;
+		__entry->audited	= sad->audited;
+		__entry->result		= sad->result;
+		__assign_str(tcontext, tcontext);
+		__assign_str(scontext, scontext);
+		__assign_str(tclass, tclass);
+	),
+
+	TP_printk("requested=0x%x denied=0x%x audited=0x%x result=%d scontext=%s tcontext=%s tclass=%s",
+		__entry->requested, __entry->denied, __entry->audited, __entry->result,
+		__get_str(scontext), __get_str(tcontext), __get_str(tclass)
+	)
+);
+
+#endif
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

scripts/selinux/mdp/mdp.c

@@ -35,6 +35,9 @@ struct security_class_mapping {
 
 #include "classmap.h"
 #include "initial_sid_to_string.h"
+#include "policycap_names.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 
 int main(int argc, char *argv[])
 {
@@ -115,6 +118,10 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	/* enable all policy capabilities */
+	for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
+		fprintf(fout, "policycap %s;\n", selinux_policycap_names[i]);
+
 	/* types, roles, and allows */
 	fprintf(fout, "type base_t;\n");
 	fprintf(fout, "role base_r;\n");

security/selinux/avc.c

@@ -31,6 +31,9 @@
 #include "avc_ss.h"
 #include "classmap.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/avc.h>
+
 #define AVC_CACHE_SLOTS			512
 #define AVC_DEF_CACHE_THRESHOLD		512
 #define AVC_CACHE_RECLAIM		16
@@ -702,33 +705,37 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
 {
 	struct common_audit_data *ad = a;
 	struct selinux_audit_data *sad = ad->selinux_audit_data;
-	char *scontext;
+	char *scontext = NULL;
+	char *tcontext = NULL;
+	const char *tclass = NULL;
 	u32 scontext_len;
+	u32 tcontext_len;
 	int rc;
 
 	rc = security_sid_to_context(sad->state, sad->ssid, &scontext,
 				     &scontext_len);
 	if (rc)
 		audit_log_format(ab, " ssid=%d", sad->ssid);
-	else {
+	else
 		audit_log_format(ab, " scontext=%s", scontext);
-		kfree(scontext);
-	}
 
-	rc = security_sid_to_context(sad->state, sad->tsid, &scontext,
-				     &scontext_len);
+	rc = security_sid_to_context(sad->state, sad->tsid, &tcontext,
+				     &tcontext_len);
 	if (rc)
 		audit_log_format(ab, " tsid=%d", sad->tsid);
-	else {
-		audit_log_format(ab, " tcontext=%s", scontext);
-		kfree(scontext);
-	}
+	else
+		audit_log_format(ab, " tcontext=%s", tcontext);
 
-	audit_log_format(ab, " tclass=%s", secclass_map[sad->tclass-1].name);
+	tclass = secclass_map[sad->tclass-1].name;
+	audit_log_format(ab, " tclass=%s", tclass);
 
 	if (sad->denied)
 		audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1);
 
+	trace_selinux_audited(sad, scontext, tcontext, tclass);
+	kfree(tcontext);
+	kfree(scontext);
+
 	/* in case of invalid context report also the actual context string */
 	rc = security_sid_to_context_inval(sad->state, sad->ssid, &scontext,
 					   &scontext_len);

security/selinux/hooks.c

@@ -1978,7 +1978,7 @@ static inline u32 file_to_av(struct file *file)
 }
 
 /*
- * Convert a file to an access vector and include the correct open
+ * Convert a file to an access vector and include the correct
  * open permission.
  */
 static inline u32 open_file_to_av(struct file *file)
@@ -3271,6 +3271,9 @@ static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
 	}
 
+	if (!selinux_initialized(&selinux_state))
+		return 0;
+
 	/* No one is allowed to remove a SELinux security label.
 	   You can change the label, but all data must be labeled. */
 	return -EACCES;
@@ -3709,7 +3712,7 @@ static int selinux_mmap_file(struct file *file, unsigned long reqprot,
 			return rc;
 	}
 
-	if (selinux_state.checkreqprot)
+	if (checkreqprot_get(&selinux_state))
 		prot = reqprot;
 
 	return file_map_prot_check(file, prot,
@@ -3723,7 +3726,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
 	const struct cred *cred = current_cred();
 	u32 sid = cred_sid(cred);
 
-	if (selinux_state.checkreqprot)
+	if (checkreqprot_get(&selinux_state))
 		prot = reqprot;
 
 	if (default_noexec &&
@@ -4438,7 +4441,7 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
  *
  * If @skb_sid is valid then the user:role:type information from @sk_sid is
  * combined with the MLS information from @skb_sid in order to create
- * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy
+ * @conn_sid.  If @skb_sid is not valid then @conn_sid is simply a copy
  * of @sk_sid.  Returns zero on success, negative values on failure.
  *
  */
@@ -5308,7 +5311,7 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
 
 			/* As selinux_sctp_bind_connect() is called by the
 			 * SCTP protocol layer, the socket is already locked,
-			 * therefore selinux_netlbl_socket_connect_locked() is
+			 * therefore selinux_netlbl_socket_connect_locked()
 			 * is called here. The situations handled are:
 			 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
 			 * whenever a new IP address is added or when a new
@@ -7225,10 +7228,10 @@ static __init int selinux_init(void)
 
 	memset(&selinux_state, 0, sizeof(selinux_state));
 	enforcing_set(&selinux_state, selinux_enforcing_boot);
-	selinux_state.checkreqprot = selinux_checkreqprot_boot;
-	selinux_ss_init(&selinux_state.ss);
+	checkreqprot_set(&selinux_state, selinux_checkreqprot_boot);
 	selinux_avc_init(&selinux_state.avc);
 	mutex_init(&selinux_state.status_lock);
+	mutex_init(&selinux_state.policy_mutex);
 
 	/* Set the security state for the initial task. */
 	cred_init_security();

security/selinux/include/conditional.h

@@ -13,7 +13,7 @@
 
 #include "security.h"
 
-int security_get_bools(struct selinux_state *state,
+int security_get_bools(struct selinux_policy *policy,
 		       u32 *len, char ***names, int **values);
 
 int security_set_bools(struct selinux_state *state, u32 len, int *values);

security/selinux/include/policycap.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SELINUX_POLICYCAP_H_
+#define _SELINUX_POLICYCAP_H_
+
+/* Policy capabilities */
+enum {
+	POLICYDB_CAPABILITY_NETPEER,
+	POLICYDB_CAPABILITY_OPENPERM,
+	POLICYDB_CAPABILITY_EXTSOCKCLASS,
+	POLICYDB_CAPABILITY_ALWAYSNETWORK,
+	POLICYDB_CAPABILITY_CGROUPSECLABEL,
+	POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION,
+	POLICYDB_CAPABILITY_GENFS_SECLABEL_SYMLINKS,
+	__POLICYDB_CAPABILITY_MAX
+};
+#define POLICYDB_CAPABILITY_MAX (__POLICYDB_CAPABILITY_MAX - 1)
+
+extern const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX];
+
+#endif /* _SELINUX_POLICYCAP_H_ */

security/selinux/include/policycap_names.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SELINUX_POLICYCAP_NAMES_H_
+#define _SELINUX_POLICYCAP_NAMES_H_
+
+#include "policycap.h"
+
+/* Policy capability names */
+const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
+	"network_peer_controls",
+	"open_perms",
+	"extended_socket_class",
+	"always_check_network",
+	"cgroup_seclabel",
+	"nnp_nosuid_transition",
+	"genfs_seclabel_symlinks"
+};
+
+#endif /* _SELINUX_POLICYCAP_NAMES_H_ */