diff options
| author | NeilBrown <neilb@suse.de> | 2012-12-13 15:14:36 +1100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-01-03 03:33:38 +0000 |
| commit | 6f744386e26b664c948361d1ee539f258e4c2f8b (patch) | |
| tree | 833d3d269ebb3fcfe86829927644a65c2292b425 | |
| parent | 61252278ee286b891e23dc0009aed1a9da1f0b0e (diff) | |
NFS: avoid NULL dereference in nfs_destroy_server
commit f259613a1e4b44a0cf85a5dafd931be96ee7c9e5 upstream.
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.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 873bf00d51a2..d03a40019f9f 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -672,8 +672,7 @@ static int nfs_create_rpc_client(struct nfs_client *clp, */ 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); } |