ipc ns: fix memory leak (idr)

We have apparently had a memory leak since 7ca7e56 "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 <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
oleg-nesterov · Dec 16, 2009 · 7d6feeb · 7d6feeb
1 parent 1be5396
commit 7d6feeb
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diff --git 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
@@ -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
@@ -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
-Original file line number
+Diff line change
@@ Expand Up / @@ -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
@@ Expand Down @@