Re: [syzbot] [input?] KASAN: null-ptr-deref Read in input_event

[Hillf Danton]

On Sun, 05 Jan 2025 00:31:21 -0800
> syzbot found the following issue on:
> 
> HEAD commit:    f097a36ef88d dt-bindings: usb: qcom,dwc3: Add QCS615 to US..
> git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17e2a8b0580000

#syz test

--- l/drivers/hid/hid-appleir.c
+++ y/drivers/hid/hid-appleir.c
@@ -150,12 +150,16 @@ static int get_key(int data)
 
 static void key_up(struct hid_device *hid, struct appleir *appleir, int key)
 {
+	if (!appleir->input_dev)
+		return;
 	input_report_key(appleir->input_dev, key, 0);
 	input_sync(appleir->input_dev);
 }
 
 static void key_down(struct hid_device *hid, struct appleir *appleir, int key)
 {
+	if (!appleir->input_dev)
+		return;
 	input_report_key(appleir->input_dev, key, 1);
 	input_sync(appleir->input_dev);
 }
--