ipc ns: fix memory leak (idr)

We have apparently had a memory leak since
7ca7e564e049d8b350ec9d958ff25eaa24226352 "ipc: store ipcs into IDRs" in
2007.  The idr of which 3 exist for each ipc namespace is never freed.

This patch simply frees them when the ipcns is freed.  I don't believe any
idr_remove() are done from rcu (and could therefore be delayed until after
this idr_destroy()), so the patch should be safe.  Some quick testing
showed no harm, and the memory leak fixed.

Caught by kmemleak.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/ipc/msg.c b/ipc/msg.c
index 085bd58f2f07..af42ef8900a6 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -125,6 +125,7 @@ void msg_init_ns(struct ipc_namespace *ns)
 void msg_exit_ns(struct ipc_namespace *ns)
 {
         free_ipcs(ns, &msg_ids(ns), freeque);
+        idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
 }
 #endif