kernfs: use simple_xattrs for security attributes

Replace the special handling of security xattrs with simple_xattrs, as
is already done for the trusted xattrs. This simplifies the code and
allows LSMs to use more than just a single xattr to do their business.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

3 files changed, 2 insertions, 58 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 1654d9136458..bd48e315347b 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -532,9 +532,6 @@ void kernfs_put(struct kernfs_node *kn)
         kfree_const(kn->name);
 
         if (kn->iattr) {
-                if (kn->iattr->ia_secdata)
-                        security_release_secctx(kn->iattr->ia_secdata,
-                                                kn->iattr->ia_secdata_len);
                 simple_xattrs_free(&kn->iattr->xattrs);
                 kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
         }
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 5c5569fb2110..a365088caa3c 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -137,23 +137,6 @@ out:
         return error;
 }
 
-static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata,
-                                  u32 *secdata_len)
-{
-        void *old_secdata;
-        size_t old_secdata_len;
-
-        old_secdata = attrs->ia_secdata;
-        old_secdata_len = attrs->ia_secdata_len;
-
-        attrs->ia_secdata = *secdata;
-        attrs->ia_secdata_len = *secdata_len;
-
-        *secdata = old_secdata;
-        *secdata_len = old_secdata_len;
-        return 0;
-}
-
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
 {
         struct kernfs_node *kn = kernfs_dentry_node(dentry);
@@ -189,15 +172,12 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
         struct kernfs_iattrs *attrs = kn->iattr;
 
         inode->i_mode = kn->mode;
-        if (attrs) {
+        if (attrs)
                 /*
                  * kernfs_node has non-default attributes get them from
                  * persistent copy in kernfs_node.
                  */
                 set_inode_attr(inode, attrs);
-                security_inode_notifysecctx(inode, attrs->ia_secdata,
-                                            attrs->ia_secdata_len);
-        }
 
         if (kernfs_type(kn) == KERNFS_DIR)
                 set_nlink(inode, kn->dir.subdirs + 2);
@@ -345,41 +325,10 @@ static const struct xattr_handler kernfs_trusted_xattr_handler = {
         .set = kernfs_xattr_set,
 };
 
-static int kernfs_security_xattr_set(const struct xattr_handler *handler,
-                                     struct dentry *unused, struct inode *inode,
-                                     const char *suffix, const void *value,
-                                     size_t size, int flags)
-{
-        struct kernfs_node *kn = inode->i_private;
-        struct kernfs_iattrs *attrs;
-        void *secdata;
-        u32 secdata_len = 0;
-        int error;
-
-        attrs = kernfs_iattrs(kn);
-        if (!attrs)
-                return -ENOMEM;
-
-        error = security_inode_setsecurity(inode, suffix, value, size, flags);
-        if (error)
-                return error;
-        error = security_inode_getsecctx(inode, &secdata, &secdata_len);
-        if (error)
-                return error;
-
-        mutex_lock(&kernfs_mutex);
-        error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
-        mutex_unlock(&kernfs_mutex);
-
-        if (secdata)
-                security_release_secctx(secdata, secdata_len);
-        return error;
-}
-
 static const struct xattr_handler kernfs_security_xattr_handler = {
         .prefix = XATTR_SECURITY_PREFIX,
         .get = kernfs_xattr_get,
-        .set = kernfs_security_xattr_set,
+        .set = kernfs_xattr_set,
 };
 
 const struct xattr_handler *kernfs_xattr_handlers[] = {
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 385a5ca0b2f6..3c437990f39a 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -25,8 +25,6 @@ struct kernfs_iattrs {
         struct timespec64       ia_atime;
         struct timespec64       ia_mtime;
         struct timespec64       ia_ctime;
-        void                    *ia_secdata;
-        u32                     ia_secdata_len;
 
         struct simple_xattrs    xattrs;
 };