From: Patrick Ho Date: Sat, 21 Aug 2021 06:56:26 +0000 (-0400) Subject: nfsd: fix error handling of register_pernet_subsys() in init_nfsd() X-Git-Tag: v5.15-rc5~17^2~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1d625050c7c2dd877e108e382b8aaf1ae3cfe1f4;p=thirdparty%2Flinux.git nfsd: fix error handling of register_pernet_subsys() in init_nfsd() 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 --- diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index c2c3d9077dc58..09ae1a0873d05 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1545,7 +1545,7 @@ 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);