From 7417896fcc7aea645fa0b89f39fa55979251dca3 Mon Sep 17 00:00:00 2001
From: Patrick Ho Patrick.Ho@netapp.com Date: Sat, 21 Aug 2021 02:56:26 -0400 Subject: [PATCH] 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 Patrick.Ho@netapp.com --- 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 c2c3d9077dc5..09ae1a0873d0 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);
On Thu, Sep 30, 2021 at 03:48:42AM +0000, Ho, Patrick wrote:
From 7417896fcc7aea645fa0b89f39fa55979251dca3 Mon Sep 17 00:00:00 2001
From: Patrick Ho Patrick.Ho@netapp.com Date: Sat, 21 Aug 2021 02:56:26 -0400 Subject: [PATCH] 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.
Whoops, thanks for catching this. I assume Chuck will pick it up.
Acked-by: J. Bruce Fields bfields@redhat.com
--b.
Fixes: bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") Cc: stable@vger.kernel.org Signed-off-by: Patrick Ho Patrick.Ho@netapp.com
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 c2c3d9077dc5..09ae1a0873d0 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); -- 2.17.1
On Sep 30, 2021, at 10:16 AM, J. Bruce Fields bfields@fieldses.org wrote:
On Thu, Sep 30, 2021 at 03:48:42AM +0000, Ho, Patrick wrote:
From 7417896fcc7aea645fa0b89f39fa55979251dca3 Mon Sep 17 00:00:00 2001
From: Patrick Ho Patrick.Ho@netapp.com Date: Sat, 21 Aug 2021 02:56:26 -0400 Subject: [PATCH] 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.
Whoops, thanks for catching this. I assume Chuck will pick it up.
Applied to the for-next branch at
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git
Acked-by: J. Bruce Fields bfields@redhat.com
--b.
Fixes: bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") Cc: stable@vger.kernel.org Signed-off-by: Patrick Ho Patrick.Ho@netapp.com
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 c2c3d9077dc5..09ae1a0873d0 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); -- 2.17.1
-- Chuck Lever
linux-stable-mirror@lists.linaro.org
-
Chuck Lever III -
Ho, Patrick -
J. Bruce Fields