The android_fence_release() function checks for active sync points by calling list_empty() on the list head embedded on the sync point. However, it is only valid to use list_empty() on nodes that have been initialized with INIT_LIST_HEAD() or list_del_init().
Because the list entry has likely been removed from the active list by sync_timeline_signal(), there is a good chance that this WARN_ON_ONCE() will be hit due to dangling pointers pointing at freed memory (even though the sync drivers did nothing wrong) and memory corruption will ensue as the list entry is removed for a second time, corrupting the active list. This problem can be reproduced quite easily with CONFIG_DEBUG_LIST=y and fences with more than one sync point. Signed-off-by: Alistair Strachan <alistair.strac...@imgtec.com> Cc: Maarten Lankhorst <maarten.lankho...@canonical.com> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Colin Cross <ccr...@google.com> --- drivers/staging/android/sync.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c index 7bdb62b..f83e00c 100644 --- a/drivers/staging/android/sync.c +++ b/drivers/staging/android/sync.c @@ -114,7 +114,7 @@ void sync_timeline_signal(struct sync_timeline *obj) list_for_each_entry_safe(pt, next, &obj->active_list_head, active_list) { if (fence_is_signaled_locked(&pt->base)) - list_del(&pt->active_list); + list_del_init(&pt->active_list); } spin_unlock_irqrestore(&obj->child_list_lock, flags); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/