diff options
| author | NeilBrown <neilb@suse.de> | 2012-12-13 08:14:36 +0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-12-13 08:55:56 +0400 |
| commit | f259613a1e4b44a0cf85a5dafd931be96ee7c9e5 (patch) | |
| tree | 032efdf98b5335c172b72a7659e25cde901530be /fs/nfs/client.c | |
| parent | eb96d5c97b0825d542e9c4ba5e0a22b519355166 (diff) | |
| download | linux-f259613a1e4b44a0cf85a5dafd931be96ee7c9e5.tar.xz | |
NFS: avoid NULL dereference in nfs_destroy_server
In rare circumstances, nfs_clone_server() of a v2 or v3 server can get
an error between setting server->destory (to nfs_destroy_server), and
calling nfs_start_lockd (which will set server->nlm_host).
If this happens, nfs_clone_server will call nfs_free_server which
will call nfs_destroy_server and thence nlmclnt_done(NULL). This
causes the NULL to be dereferenced.
So add a guard to only call nlmclnt_done() if ->nlm_host is not NULL.
The other guards there are irrelevant as nlm_host can only be non-NULL
if one of these flags are set - so remove those tests. (Thanks to Trond
for this suggestion).
This is suitable for any stable kernel since 2.6.25.
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/client.c')
| -rw-r--r-- | fs/nfs/client.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c index c285e0a117e4..9f3c66438d0e 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -615,8 +615,7 @@ EXPORT_SYMBOL_GPL(nfs_create_rpc_client); */ static void nfs_destroy_server(struct nfs_server *server) { - if (!(server->flags & NFS_MOUNT_LOCAL_FLOCK) || - !(server->flags & NFS_MOUNT_LOCAL_FCNTL)) + if (server->nlm_host) nlmclnt_done(server->nlm_host); } |