Commit daf5cc27 authored by Al Viro's avatar Al Viro Committed by Ilya Dryomov
Browse files

ceph: fix use-after-free on symlink traversal 



free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 187df763

fs/ceph/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -524,6 +524,7 @@ static void ceph_i_callback(struct rcu_head *head) 
	struct inode *inode = container_of(head, struct inode, i_rcu);

	struct ceph_inode_info *ci = ceph_inode(inode);



	kfree(ci->i_symlink);

	kmem_cache_free(ceph_inode_cachep, ci);

}
@@ -566,7 +567,6 @@ void ceph_destroy_inode(struct inode *inode) 
		}

	}



	kfree(ci->i_symlink);

	while ((n = rb_first(&ci->i_fragtree)) != NULL) {

		frag = rb_entry(n, struct ceph_inode_frag, node);

		rb_erase(n, &ci->i_fragtree);