Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 9625b99..717a398 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1499,7 +1499,7 @@
 			 * inode_doinit with a dentry, before these inodes could
 			 * be used again by userspace.
 			 */
-			goto out;
+			goto out_invalid;
 		}
 
 		rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
@@ -1554,7 +1554,7 @@
 			 * could be used again by userspace.
 			 */
 			if (!dentry)
-				goto out;
+				goto out_invalid;
 			rc = selinux_genfs_get_sid(dentry, sclass,
 						   sbsec->flags, &sid);
 			if (rc) {
@@ -1579,11 +1579,10 @@
 out:
 	spin_lock(&isec->lock);
 	if (isec->initialized == LABEL_PENDING) {
-		if (!sid || rc) {
+		if (rc) {
 			isec->initialized = LABEL_INVALID;
 			goto out_unlock;
 		}
-
 		isec->initialized = LABEL_INITIALIZED;
 		isec->sid = sid;
 	}
@@ -1591,6 +1590,15 @@
 out_unlock:
 	spin_unlock(&isec->lock);
 	return rc;
+
+out_invalid:
+	spin_lock(&isec->lock);
+	if (isec->initialized == LABEL_PENDING) {
+		isec->initialized = LABEL_INVALID;
+		isec->sid = sid;
+	}
+	spin_unlock(&isec->lock);
+	return 0;
 }
 
 /* Convert a Linux signal to an access vector. */
@@ -2766,6 +2774,14 @@
 		return path_has_perm(cred, path, FILE__MOUNTON);
 }
 
+static int selinux_move_mount(const struct path *from_path,
+			      const struct path *to_path)
+{
+	const struct cred *cred = current_cred();
+
+	return path_has_perm(cred, to_path, FILE__MOUNTON);
+}
+
 static int selinux_umount(struct vfsmount *mnt, int flags)
 {
 	const struct cred *cred = current_cred();
@@ -3008,14 +3024,14 @@
 	if (IS_ERR(isec))
 		return PTR_ERR(isec);
 
-	return avc_has_perm(&selinux_state,
-			    sid, isec->sid, isec->sclass, FILE__READ, &ad);
+	return avc_has_perm_flags(&selinux_state,
+				  sid, isec->sid, isec->sclass, FILE__READ, &ad,
+				  rcu ? MAY_NOT_BLOCK : 0);
 }
 
 static noinline int audit_inode_permission(struct inode *inode,
 					   u32 perms, u32 audited, u32 denied,
-					   int result,
-					   unsigned flags)
+					   int result)
 {
 	struct common_audit_data ad;
 	struct inode_security_struct *isec = selinux_inode(inode);
@@ -3026,7 +3042,7 @@
 
 	rc = slow_avc_audit(&selinux_state,
 			    current_sid(), isec->sid, isec->sclass, perms,
-			    audited, denied, result, &ad, flags);
+			    audited, denied, result, &ad);
 	if (rc)
 		return rc;
 	return 0;
@@ -3073,7 +3089,11 @@
 	if (likely(!audited))
 		return rc;
 
-	rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
+	/* fall back to ref-walk if we have to generate audit */
+	if (flags & MAY_NOT_BLOCK)
+		return -ECHILD;
+
+	rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
 	if (rc2)
 		return rc2;
 	return rc;
@@ -3144,6 +3164,9 @@
 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
 	}
 
+	if (!selinux_state.initialized)
+		return (inode_owner_or_capable(inode) ? 0 : -EPERM);
+
 	sbsec = inode->i_sb->s_security;
 	if (!(sbsec->flags & SBLABEL_MNT))
 		return -EOPNOTSUPP;
@@ -3227,6 +3250,15 @@
 		return;
 	}
 
+	if (!selinux_state.initialized) {
+		/* If we haven't even been initialized, then we can't validate
+		 * against a policy, so leave the label as invalid. It may
+		 * resolve to a valid label on the next revalidation try if
+		 * we've since initialized.
+		 */
+		return;
+	}
+
 	rc = security_context_to_sid_force(&selinux_state, value, size,
 					   &newsid);
 	if (rc) {
@@ -5509,40 +5541,60 @@
 
 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 {
-	int err = 0;
-	u32 perm;
+	int rc = 0;
+	unsigned int msg_len;
+	unsigned int data_len = skb->len;
+	unsigned char *data = skb->data;
 	struct nlmsghdr *nlh;
 	struct sk_security_struct *sksec = sk->sk_security;
+	u16 sclass = sksec->sclass;
+	u32 perm;
 
-	if (skb->len < NLMSG_HDRLEN) {
-		err = -EINVAL;
-		goto out;
-	}
-	nlh = nlmsg_hdr(skb);
+	while (data_len >= nlmsg_total_size(0)) {
+		nlh = (struct nlmsghdr *)data;
 
-	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
-	if (err) {
-		if (err == -EINVAL) {
+		/* NOTE: the nlmsg_len field isn't reliably set by some netlink
+		 *       users which means we can't reject skb's with bogus
+		 *       length fields; our solution is to follow what
+		 *       netlink_rcv_skb() does and simply skip processing at
+		 *       messages with length fields that are clearly junk
+		 */
+		if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
+			return 0;
+
+		rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
+		if (rc == 0) {
+			rc = sock_has_perm(sk, perm);
+			if (rc)
+				return rc;
+		} else if (rc == -EINVAL) {
+			/* -EINVAL is a missing msg/perm mapping */
 			pr_warn_ratelimited("SELinux: unrecognized netlink"
-			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
-			       " pig=%d comm=%s\n",
-			       sk->sk_protocol, nlh->nlmsg_type,
-			       secclass_map[sksec->sclass - 1].name,
-			       task_pid_nr(current), current->comm);
-			if (!enforcing_enabled(&selinux_state) ||
-			    security_get_allow_unknown(&selinux_state))
-				err = 0;
+				" message: protocol=%hu nlmsg_type=%hu sclass=%s"
+				" pid=%d comm=%s\n",
+				sk->sk_protocol, nlh->nlmsg_type,
+				secclass_map[sclass - 1].name,
+				task_pid_nr(current), current->comm);
+			if (enforcing_enabled(&selinux_state) &&
+			    !security_get_allow_unknown(&selinux_state))
+				return rc;
+			rc = 0;
+		} else if (rc == -ENOENT) {
+			/* -ENOENT is a missing socket/class mapping, ignore */
+			rc = 0;
+		} else {
+			return rc;
 		}
 
-		/* Ignore */
-		if (err == -ENOENT)
-			err = 0;
-		goto out;
+		/* move to the next message after applying netlink padding */
+		msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
+		if (msg_len >= data_len)
+			return 0;
+		data_len -= msg_len;
+		data += msg_len;
 	}
 
-	err = sock_has_perm(sk, perm);
-out:
-	return err;
+	return rc;
 }
 
 #ifdef CONFIG_NETFILTER
@@ -6834,6 +6886,8 @@
 	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
 	LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt),
 
+	LSM_HOOK_INIT(move_mount, selinux_move_mount),
+
 	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
 	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),