HID: hidraw: Add spinlock in struct hidraw to protect list

It is unsafe to call list_for_each_entry in hidraw_report_event to
traverse each hidraw_list node without a lock protection, the list
could be modified if someone calls hidraw_release and list_del to
remove itself from the list, this can cause hidraw_report_event
to touch a deleted list struct and panic.

To prevent this, introduce a spinlock in struct hidraw to protect
list from concurrent access.

Signed-off-by: Yonghua Zheng <younghua.zheng@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/hidraw.h b/include/linux/hidraw.h
index 2451662c728a..ddf52612eed8 100644
--- a/include/linux/hidraw.h
+++ b/include/linux/hidraw.h
@@ -23,6 +23,7 @@ struct hidraw {
 	wait_queue_head_t wait;
 	struct hid_device *hid;
 	struct device *dev;
+	spinlock_t list_lock;
 	struct list_head list;
 };