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>

diff --git a/ipc/msg.c b/ipc/msg.c
index 085bd58f2f07a348746f917dc491031f3f1c19af..af42ef8900a6418e3dce715316800e1bbb6da4df 100644 (file)
--- 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
 

diff --git a/ipc/sem.c b/ipc/sem.c
index 87c2b641fd7b475b192adf281fcdc1f5cf249893..2f2a47959576964c200e7493464818da982c3e7a 100644 (file)
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -129,6 +129,7 @@ void sem_init_ns(struct ipc_namespace *ns)
 void sem_exit_ns(struct ipc_namespace *ns)
 {
        free_ipcs(ns, &sem_ids(ns), freeary);
+       idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr);
 }
 #endif
 

diff --git a/ipc/shm.c b/ipc/shm.c
index 11bec626c228c98d5f3e0512f9c6f0dd40f424dc..e9b039f74129e3e5e47d34c1e91a128b29fa45df 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -101,6 +101,7 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 void shm_exit_ns(struct ipc_namespace *ns)
 {
        free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
+       idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
 }
 #endif