async: initialise list heads to fix crash

9fdb04cdc55 ("async: replace list of active domains with global list
of pending items") added a struct list_head global_list in struct
async_entry, which isn't initialised.  This means that if
!domain->registered at __async_schedule(), then list_del_init() will
be called on the list head in async_run_entry_fn with both pointers
NULL, causing a crash.  This is fixed by initialising both the
global_list and domain_list list_heads after kzalloc'ing the entry.

This was noticed due to dapm_power_widgets() which uses
ASYNC_DOMAIN_EXCLUSIVE, which initialises the domain->registered to 0.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: James Hogan <james.hogan@imgtec.com>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/async.c b/kernel/async.c
index 6958000eeb44..8ddee2c3e5b0 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -172,6 +172,8 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a
                 ptr(data, newcookie);
                 return newcookie;
         }
+        INIT_LIST_HEAD(&entry->domain_list);
+        INIT_LIST_HEAD(&entry->global_list);
         INIT_WORK(&entry->work, async_run_entry_fn);
         entry->func = ptr;
         entry->data = data;