Messages in this thread Patch in this message | | | Date | Sat, 20 Oct 2012 00:15:18 +0100 | From | Ben Hutchings <> | Subject | Re: [ 02/37] lockd: use rpc clients cl_nodename for id encoding |
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On Thu, Oct 18, 2012 at 08:16:25PM -0700, Greg Kroah-Hartman wrote: > 3.0-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Stanislav Kinsbursky <skinsbursky@parallels.com> > > commit 303a7ce92064c285a04c870f2dc0192fdb2968cb upstream. > > Taking hostname from uts namespace if not safe, because this cuold be > performind during umount operation on child reaper death. And in this case > current->nsproxy is NULL already.
In this case (3.0.y) you haven't included the following change (commit cb7323fffa85 'lockd: create and use per-net NSM RPC clients on MON/UNMON requests') that makes lockd actually use cl_nodename. I think this patch alone won't fix the bug, as nsm_args::nodename can end up pointing to freed memory.
(I also wonder whether clients should really be per-net or per UTS namespace, and whether those should be orthogonal namespaces at all.)
Ben.
[....] > --- a/fs/lockd/mon.c > +++ b/fs/lockd/mon.c > @@ -40,6 +40,7 @@ struct nsm_args { > u32 proc; > > char *mon_name; > + char *nodename; > }; > > struct nsm_res { > @@ -93,6 +94,7 @@ static int nsm_mon_unmon(struct nsm_hand > .vers = 3, > .proc = NLMPROC_NSM_NOTIFY, > .mon_name = nsm->sm_mon_name, > + .nodename = utsname()->nodename, > }; > struct rpc_message msg = { > .rpc_argp = &args, > @@ -429,7 +431,7 @@ static void encode_my_id(struct xdr_stre > { > __be32 *p; > > - encode_nsm_string(xdr, utsname()->nodename); > + encode_nsm_string(xdr, argp->nodename); > p = xdr_reserve_space(xdr, 4 + 4 + 4); > *p++ = cpu_to_be32(argp->prog); > *p++ = cpu_to_be32(argp->vers);
-- Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camus
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