From 193490dbe5ba5a3c8aa0e61312d67142483c9498 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 10 Feb 2020 22:51:08 +0100 Subject: ceph: canonicalize server path in place commit b27a939e8376a3f1ed09b9c33ef44d20f18ec3d0 upstream. syzbot reported that 4fbc0c711b24 ("ceph: remove the extra slashes in the server path") had caused a regression where an allocation could be done under a spinlock -- compare_mount_options() is called by sget_fc() with sb_lock held. We don't really need the supplied server path, so canonicalize it in place and compare it directly. To make this work, the leading slash is kept around and the logic in ceph_real_mount() to skip it is restored. CEPH_MSG_CLIENT_SESSION now reports the same (i.e. canonicalized) path, with the leading slash of course. Fixes: 4fbc0c711b24 ("ceph: remove the extra slashes in the server path") Reported-by: syzbot+98704a51af8e3d9425a9@syzkaller.appspotmail.com Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton Signed-off-by: Luis Henriques Signed-off-by: Greg Kroah-Hartman --- fs/ceph/super.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ceph/super.h') diff --git a/fs/ceph/super.h b/fs/ceph/super.h index f98d9247f9cb..bb12c9f3a218 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -92,7 +92,7 @@ struct ceph_mount_options { char *snapdir_name; /* default ".snap" */ char *mds_namespace; /* default NULL */ - char *server_path; /* default "/" */ + char *server_path; /* default NULL (means "/") */ char *fscache_uniq; /* default NULL */ }; -- cgit v1.2.3