From 1832397d8ce4de6827fb102a70649c63e7a2f9a2 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Sat, 8 Oct 2016 10:14:37 -0300 Subject: [PATCH] dlm: free workqueues after the connections commit 3a8db79889ce16930aff19b818f5b09651bb7644 upstream. After backporting commit ee44b4bc054a ("dlm: use sctp 1-to-1 API") series to a kernel with an older workqueue which didn't use RCU yet, it was noticed that we are freeing the workqueues in dlm_lowcomms_stop() too early as free_conn() will try to access that memory for canceling the queued works if any. This issue was introduced by commit 0d737a8cfd83 as before it such attempt to cancel the queued works wasn't performed, so the issue was not present. This patch fixes it by simply inverting the free order. Fixes: 0d737a8cfd83 ("dlm: fix race while closing connections") Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman --- fs/dlm/lowcomms.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 3a37bd3f9637..9d7a4a714907 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -1607,16 +1607,12 @@ void dlm_lowcomms_stop(void) mutex_lock(&connections_lock); dlm_allow_conn = 0; foreach_conn(stop_conn); + clean_writequeues(); + foreach_conn(free_conn); mutex_unlock(&connections_lock); work_stop(); - mutex_lock(&connections_lock); - clean_writequeues(); - - foreach_conn(free_conn); - - mutex_unlock(&connections_lock); kmem_cache_destroy(con_cache); } -- 2.34.1