From 12d4b179022ac7d07aa263b46159779536b3c6a6 Mon Sep 17 00:00:00 2001 From: Patrick Ho Date: Sat, 21 Aug 2021 02:56:26 -0400 Subject: [PATCH] nfsd: fix error handling of register_pernet_subsys() in init_nfsd() commit 1d625050c7c2dd877e108e382b8aaf1ae3cfe1f4 upstream. init_nfsd() should not unregister pernet subsys if the register fails but should instead unwind from the last successful operation which is register_filesystem(). Unregistering a failed register_pernet_subsys() call can result in a kernel GPF as revealed by programmatically injecting an error in register_pernet_subsys(). Verified the fix handled failure gracefully with no lingering nfsd entry in /proc/filesystems. This change was introduced by the commit bd5ae9288d64 ("nfsd: register pernet ops last, unregister first"), the original error handling logic was correct. Fixes: bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") Cc: stable@vger.kernel.org Signed-off-by: Patrick Ho Acked-by: J. Bruce Fields Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfsctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 0759e58..ddf2b37 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1547,7 +1547,7 @@ static int __init init_nfsd(void) goto out_free_all; return 0; out_free_all: - unregister_pernet_subsys(&nfsd_net_ops); + unregister_filesystem(&nfsd_fs_type); out_free_exports: remove_proc_entry("fs/nfs/exports", NULL); remove_proc_entry("fs/nfs", NULL); -- 2.7.4