Re: [syzbot] [pvrusb2?] KASAN: slab-use-after-free Read in pvr2_context_set_notify (2)

[Edward Adam Davis]

please test uaf in pvr2_context_set_notify

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-context.c b/drivers/media/usb/pvrusb2/pvrusb2-context.c
index 1764674de98b..e93bca93ce4c 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-context.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-context.c
@@ -267,9 +267,9 @@ static void pvr2_context_exit(struct pvr2_context *mp)
 void pvr2_context_disconnect(struct pvr2_context *mp)
 {
 	pvr2_hdw_disconnect(mp->hdw);
-	mp->disconnect_flag = !0;
 	if (!pvr2_context_shutok())
 		pvr2_context_notify(mp);
+	mp->disconnect_flag = !0;
 }