From 0ad95472bf169a3501991f8f33f5147f792a8116 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Wed, 23 Sep 2015 15:49:29 +0300 Subject: lockd: create NSM handles per net namespace Commit cb7323fffa85 ("lockd: create and use per-net NSM RPC clients on MON/UNMON requests") introduced per-net NSM RPC clients. Unfortunately this doesn't make any sense without per-net nsm_handle. E.g. the following scenario could happen Two hosts (X and Y) in different namespaces (A and B) share the same nsm struct. 1. nsm_monitor(host_X) called => NSM rpc client created, nsm->sm_monitored bit set. 2. nsm_mointor(host-Y) called => nsm->sm_monitored already set, we just exit. Thus in namespace B ln->nsm_clnt == NULL. 3. host X destroyed => nsm->sm_count decremented to 1 4. host Y destroyed => nsm_unmonitor() => nsm_mon_unmon() => NULL-ptr dereference of *ln->nsm_clnt So this could be fixed by making per-net nsm_handles list, instead of global. Thus different net namespaces will not be able share the same nsm_handle. Signed-off-by: Andrey Ryabinin Cc: Signed-off-by: J. Bruce Fields --- fs/lockd/netns.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/lockd/netns.h') diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h index 097bfa3adb1c..89fe011b1335 100644 --- a/fs/lockd/netns.h +++ b/fs/lockd/netns.h @@ -15,6 +15,7 @@ struct lockd_net { spinlock_t nsm_clnt_lock; unsigned int nsm_users; struct rpc_clnt *nsm_clnt; + struct list_head nsm_handles; }; extern int lockd_net_id; -- cgit v1.2.3