selinux: add security in-core xattr support for pstore and debugfs

- add "pstore" and "debugfs" to list of in-core exceptions
- change fstype checks to boolean equation
- change from strncmp to strcmp for checking

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
[PM: tweaked the subject line prefix to "selinux"]
Signed-off-by: Paul Moore <pmoore@redhat.com>

1 files changed, 8 insertions, 17 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c253caa90bb4..87a915656eab 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -401,23 +401,14 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
 {
         struct superblock_security_struct *sbsec = sb->s_security;
 
-        if (sbsec->behavior == SECURITY_FS_USE_XATTR ||
-            sbsec->behavior == SECURITY_FS_USE_TRANS ||
-            sbsec->behavior == SECURITY_FS_USE_TASK)
-                return 1;
-
-        /* Special handling for sysfs. Is genfs but also has setxattr handler*/
-        if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
-                return 1;
-
-        /*
-         * Special handling for rootfs. Is genfs but supports
-         * setting SELinux context on in-core inodes.
-         */
-        if (strncmp(sb->s_type->name, "rootfs", sizeof("rootfs")) == 0)
-                return 1;
-
-        return 0;
+        return sbsec->behavior == SECURITY_FS_USE_XATTR ||
+                sbsec->behavior == SECURITY_FS_USE_TRANS ||
+                sbsec->behavior == SECURITY_FS_USE_TASK ||
+                /* Special handling. Genfs but also in-core setxattr handler */
+                !strcmp(sb->s_type->name, "sysfs") ||
+                !strcmp(sb->s_type->name, "pstore") ||
+                !strcmp(sb->s_type->name, "debugfs") ||
+                !strcmp(sb->s_type->name, "rootfs");
 }
 
 static int sb_finish_set_opts(struct super_block *sb)