Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 08/52] nfsd: fix error handling of register_pernet_subsys() in init_nfsd() | Date | Mon, 11 Oct 2021 15:45:37 +0200 |
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From: Patrick Ho <Patrick.Ho@netapp.com>
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 <Patrick.Ho@netapp.com> Acked-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/nfsd/nfsctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1549,7 +1549,7 @@ 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);
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