Merge tag 'selinux-pr-20250323' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

59c017ce · Linus Torvalds <[email protected]> · 2025-03-25 15:52:32 -07:00

Pull selinux updates from Paul Moore:

 - Add additional SELinux access controls for kernel file reads/loads

   The SELinux kernel file read/load access controls were never updated
   beyond the initial kernel module support, this pull request adds
   support for firmware, kexec, policies, and x.509 certificates.

 - Add support for wildcards in network interface names

   There are a number of userspace tools which auto-generate network
   interface names using some pattern of <XXXX>-<NN> where <XXXX> is a
   fixed string, e.g. "podman", and <NN> is a increasing counter.
   Supporting wildcards in the SELinux policy for network interfaces
   simplifies the policy associted with these interfaces.

 - Fix a potential problem in the kernel read file SELinux code

   SELinux should always check the file label in the
   security_kernel_read_file() LSM hook, regardless of if the file is
   being read in chunks. Unfortunately, the existing code only
   considered the file label on the first chunk; this pull request fixes
   this problem.

   There is more detail in the individual commit, but thankfully the
   existing code didn't expose a bug due to multi-stage reads only
   taking place in one driver, and that driver loading a file type that
   isn't targeted by the SELinux policy.

 - Fix the subshell error handling in the example policy loader

   Minor fix to SELinux example policy loader in scripts/selinux due to
   an undesired interaction with subshells and errexit.

* tag 'selinux-pr-20250323' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: get netif_wildcard policycap from policy instead of cache
  selinux: support wildcard network interface names
  selinux: Chain up tool resolving errors in install_policy.sh
  selinux: add permission checks for loading other kinds of kernel files
  selinux: always check the file label in selinux_kernel_read_file()
  selinux: fix spelling error

Commit: 59c017ce9ec77953ca5198b41d4101f57dd4af0d
Parents: 05457026 · a3d3043e

Merge commit. Changes below are compared with the first parent: 05457026.

Changes

8 files changed · +79 −25

File	Status	Add	Del	Content
scripts/selinux/install_policy.sh	modified	+6	−9	View file
security/selinux/avc.c	modified	+1	−1	View file
security/selinux/hooks.c	modified	+48	−10	View file
security/selinux/include/classmap.h	modified	+3	−1	View file
security/selinux/include/policycap.h	modified	+1	−0	View file
security/selinux/include/policycap_names.h	modified	+1	−0	View file
security/selinux/include/security.h	modified	+7	−1	View file
security/selinux/ss/services.c	modified	+12	−3	View file

scripts/selinux/install_policy.sh

View file

diff --git a/scripts/selinux/install_policy.sh b/scripts/selinux/install_policy.sh
index 2408679..db40237 100755
--- a/scripts/selinux/install_policy.sh
+++ b/scripts/selinux/install_policy.sh
@@ -6,27 +6,24 @@ if [ `id -u` -ne 0 ]; then
 	exit 1
 fi
 
-SF=`which setfiles`
-if [ $? -eq 1 ]; then
+SF=`which setfiles` || {
 	echo "Could not find setfiles"
 	echo "Do you have policycoreutils installed?"
 	exit 1
-fi
+}
 
-CP=`which checkpolicy`
-if [ $? -eq 1 ]; then
+CP=`which checkpolicy` || {
 	echo "Could not find checkpolicy"
 	echo "Do you have checkpolicy installed?"
 	exit 1
-fi
+}
 VERS=`$CP -V | awk '{print $1}'`
 
-ENABLED=`which selinuxenabled`
-if [ $? -eq 1 ]; then
+ENABLED=`which selinuxenabled` || {
 	echo "Could not find selinuxenabled"
 	echo "Do you have libselinux-utils installed?"
 	exit 1
-fi
+}
 
 if selinuxenabled; then
     echo "SELinux is already enabled"

security/selinux/avc.c

View file

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 1f2680b..4b4837a 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -936,7 +936,7 @@ static void avc_flush(void)
 
 		spin_lock_irqsave(lock, flag);
 		/*
-		 * With preemptable RCU, the outer spinlock does not
+		 * With preemptible RCU, the outer spinlock does not
 		 * prevent RCU grace periods from ending.
 		 */
 		rcu_read_lock();

security/selinux/hooks.c

View file

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 60b1cbd..7150c95 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4099,7 +4099,7 @@ static int selinux_kernel_module_request(char *kmod_name)
 			    SYSTEM__MODULE_REQUEST, &ad);
 }
 
-static int selinux_kernel_module_from_file(struct file *file)
+static int selinux_kernel_load_from_file(struct file *file, u32 requested)
 {
 	struct common_audit_data ad;
 	struct inode_security_struct *isec;
@@ -4107,12 +4107,8 @@ static int selinux_kernel_module_from_file(struct file *file)
 	u32 sid = current_sid();
 	int rc;
 
-	/* init_module */
 	if (file == NULL)
-		return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
-					SYSTEM__MODULE_LOAD, NULL);
-
-	/* finit_module */
+		return avc_has_perm(sid, sid, SECCLASS_SYSTEM, requested, NULL);
 
 	ad.type = LSM_AUDIT_DATA_FILE;
 	ad.u.file = file;
@@ -4125,8 +4121,7 @@ static int selinux_kernel_module_from_file(struct file *file)
 	}
 
 	isec = inode_security(file_inode(file));
-	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
-				SYSTEM__MODULE_LOAD, &ad);
+	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM, requested, &ad);
 }
 
 static int selinux_kernel_read_file(struct file *file,
@@ -4135,9 +4130,30 @@ static int selinux_kernel_read_file(struct file *file,
 {
 	int rc = 0;
 
+	BUILD_BUG_ON_MSG(READING_MAX_ID > 7,
+			 "New kernel_read_file_id introduced; update SELinux!");
+
 	switch (id) {
+	case READING_FIRMWARE:
+		rc = selinux_kernel_load_from_file(file, SYSTEM__FIRMWARE_LOAD);
+		break;
 	case READING_MODULE:
-		rc = selinux_kernel_module_from_file(contents ? file : NULL);
+		rc = selinux_kernel_load_from_file(file, SYSTEM__MODULE_LOAD);
+		break;
+	case READING_KEXEC_IMAGE:
+		rc = selinux_kernel_load_from_file(file,
+						   SYSTEM__KEXEC_IMAGE_LOAD);
+		break;
+	case READING_KEXEC_INITRAMFS:
+		rc = selinux_kernel_load_from_file(file,
+						SYSTEM__KEXEC_INITRAMFS_LOAD);
+		break;
+	case READING_POLICY:
+		rc = selinux_kernel_load_from_file(file, SYSTEM__POLICY_LOAD);
+		break;
+	case READING_X509_CERTIFICATE:
+		rc = selinux_kernel_load_from_file(file,
+						SYSTEM__X509_CERTIFICATE_LOAD);
 		break;
 	default:
 		break;
@@ -4150,9 +4166,31 @@ static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
 {
 	int rc = 0;
 
+	BUILD_BUG_ON_MSG(LOADING_MAX_ID > 7,
+			 "New kernel_load_data_id introduced; update SELinux!");
+
 	switch (id) {
+	case LOADING_FIRMWARE:
+		rc = selinux_kernel_load_from_file(NULL, SYSTEM__FIRMWARE_LOAD);
+		break;
 	case LOADING_MODULE:
-		rc = selinux_kernel_module_from_file(NULL);
+		rc = selinux_kernel_load_from_file(NULL, SYSTEM__MODULE_LOAD);
+		break;
+	case LOADING_KEXEC_IMAGE:
+		rc = selinux_kernel_load_from_file(NULL,
+						   SYSTEM__KEXEC_IMAGE_LOAD);
+		break;
+	case LOADING_KEXEC_INITRAMFS:
+		rc = selinux_kernel_load_from_file(NULL,
+						SYSTEM__KEXEC_INITRAMFS_LOAD);
+		break;
+	case LOADING_POLICY:
+		rc = selinux_kernel_load_from_file(NULL,
+						   SYSTEM__POLICY_LOAD);
+		break;
+	case LOADING_X509_CERTIFICATE:
+		rc = selinux_kernel_load_from_file(NULL,
+						SYSTEM__X509_CERTIFICATE_LOAD);
 		break;
 	default:
 		break;

security/selinux/include/classmap.h

View file

diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index f897095..04a9b48 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -63,7 +63,9 @@ const struct security_class_mapping secclass_map[] = {
 	{ "process2", { "nnp_transition", "nosuid_transition", NULL } },
 	{ "system",
 	  { "ipc_info", "syslog_read", "syslog_mod", "syslog_console",
-	    "module_request", "module_load", NULL } },
+	    "module_request", "module_load", "firmware_load",
+	    "kexec_image_load", "kexec_initramfs_load", "policy_load",
+	    "x509_certificate_load", NULL } },
 	{ "capability", { COMMON_CAP_PERMS, NULL } },
 	{ "filesystem",
 	  { "mount", "remount", "unmount", "getattr", "relabelfrom",

security/selinux/include/policycap.h

View file

diff --git a/security/selinux/include/policycap.h b/security/selinux/include/policycap.h
index 079679f..bd402d3 100644
--- a/security/selinux/include/policycap.h
+++ b/security/selinux/include/policycap.h
@@ -15,6 +15,7 @@ enum {
 	POLICYDB_CAP_IOCTL_SKIP_CLOEXEC,
 	POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT,
 	POLICYDB_CAP_NETLINK_XPERM,
+	POLICYDB_CAP_NETIF_WILDCARD,
 	__POLICYDB_CAP_MAX
 };
 #define POLICYDB_CAP_MAX (__POLICYDB_CAP_MAX - 1)

security/selinux/include/policycap_names.h

View file

diff --git a/security/selinux/include/policycap_names.h b/security/selinux/include/policycap_names.h
index e080827..ac1342d 100644
--- a/security/selinux/include/policycap_names.h
+++ b/security/selinux/include/policycap_names.h
@@ -18,6 +18,7 @@ const char *const selinux_policycap_names[__POLICYDB_CAP_MAX] = {
 	"ioctl_skip_cloexec",
 	"userspace_initial_context",
 	"netlink_xperm",
+	"netif_wildcard",
 };
 /* clang-format on */
 

security/selinux/include/security.h

View file

diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 8b4c2aa..e7827ed 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -202,6 +202,12 @@ static inline bool selinux_policycap_netlink_xperm(void)
 		selinux_state.policycap[POLICYDB_CAP_NETLINK_XPERM]);
 }
 
+static inline bool selinux_policycap_netif_wildcard(void)
+{
+	return READ_ONCE(
+		selinux_state.policycap[POLICYDB_CAP_NETIF_WILDCARD]);
+}
+
 struct selinux_policy_convert_data;
 
 struct selinux_load_state {
@@ -301,7 +307,7 @@ int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid);
 
 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid);
 
-int security_netif_sid(char *name, u32 *if_sid);
+int security_netif_sid(const char *name, u32 *if_sid);
 
 int security_node_sid(u16 domain, void *addr, u32 addrlen, u32 *out_sid);
 

security/selinux/ss/services.c

View file

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 8478842..e431772 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -46,6 +46,7 @@
 #include <linux/in.h>
 #include <linux/sched.h>
 #include <linux/audit.h>
+#include <linux/parser.h>
 #include <linux/vmalloc.h>
 #include <linux/lsm_hooks.h>
 #include <net/netlabel.h>
@@ -2572,13 +2573,14 @@ out:
  * @name: interface name
  * @if_sid: interface SID
  */
-int security_netif_sid(char *name, u32 *if_sid)
+int security_netif_sid(const char *name, u32 *if_sid)
 {
 	struct selinux_policy *policy;
 	struct policydb *policydb;
 	struct sidtab *sidtab;
 	int rc;
 	struct ocontext *c;
+	bool wildcard_support;
 
 	if (!selinux_initialized()) {
 		*if_sid = SECINITSID_NETIF;
@@ -2591,11 +2593,18 @@ retry:
 	policy = rcu_dereference(selinux_state.policy);
 	policydb = &policy->policydb;
 	sidtab = policy->sidtab;
+	wildcard_support = ebitmap_get_bit(&policydb->policycaps, POLICYDB_CAP_NETIF_WILDCARD);
 
 	c = policydb->ocontexts[OCON_NETIF];
 	while (c) {
-		if (strcmp(name, c->u.name) == 0)
-			break;
+		if (wildcard_support) {
+			if (match_wildcard(c->u.name, name))
+				break;
+		} else {
+			if (strcmp(c->u.name, name) == 0)
+				break;
+		}
+
 		c = c->next;
 	}
 