Re: [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in steam_input_open

[Hillf Danton <hdanton@sina.com>]

On Sat, 22 Feb 2025 09:01:23 -0800
> syzbot found the following issue on:
> 
> HEAD commit:    0a86e49acfbb dt-bindings: usb: samsung,exynos-dwc3 Add exy..
> 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=17c02ba4580000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  master

--- x/drivers/hid/hid-steam.c
+++ y/drivers/hid/hid-steam.c
@@ -314,6 +314,7 @@ struct steam_device {
 	u16 rumble_right;
 	unsigned int sensor_timestamp_us;
 	struct work_struct unregister_work;
+	struct work_struct unregister_work2;
 };
 
 static int steam_recv_report(struct steam_device *steam,
@@ -618,6 +619,8 @@ static void steam_input_close(struct inp
 	unsigned long flags;
 	bool set_lizard_mode;
 
+	if (dev->going_away)
+		return;
 	if (!(steam->quirks & STEAM_QUIRK_DECK)) {
 		spin_lock_irqsave(&steam->lock, flags);
 		set_lizard_mode = !steam->client_opened && lizard_mode;
@@ -1077,25 +1080,17 @@ static void steam_work_unregister_cb(str
 {
 	struct steam_device *steam = container_of(work, struct steam_device,
 							unregister_work);
-	unsigned long flags;
-	bool connected;
-	bool opened;
-
-	spin_lock_irqsave(&steam->lock, flags);
-	opened = steam->client_opened;
-	connected = steam->connected;
-	spin_unlock_irqrestore(&steam->lock, flags);
+	steam_sensors_unregister(steam);
+	steam_input_unregister(steam);
+}
 
-	if (connected) {
-		if (opened) {
-			steam_sensors_unregister(steam);
-			steam_input_unregister(steam);
-		} else {
-			steam_set_lizard_mode(steam, lizard_mode);
-			steam_input_register(steam);
-			steam_sensors_register(steam);
-		}
-	}
+static void steam_work_unregister_cb2(struct work_struct *work)
+{
+	struct steam_device *steam = container_of(work, struct steam_device,
+							unregister_work2);
+	steam_set_lizard_mode(steam, lizard_mode);
+	steam_input_register(steam);
+	steam_sensors_register(steam);
 }
 
 static bool steam_is_valve_interface(struct hid_device *hdev)
@@ -1160,7 +1155,7 @@ static void steam_client_ll_close(struct
 	connected = steam->connected && !steam->client_opened;
 	spin_unlock_irqrestore(&steam->lock, flags);
 
-	schedule_work(&steam->unregister_work);
+	schedule_work(&steam->unregister_work2);
 }
 
 static int steam_client_ll_raw_request(struct hid_device *hdev,
@@ -1253,6 +1248,7 @@ static int steam_probe(struct hid_device
 	INIT_WORK(&steam->rumble_work, steam_haptic_rumble_cb);
 	steam->sensor_timestamp_us = 0;
 	INIT_WORK(&steam->unregister_work, steam_work_unregister_cb);
+	INIT_WORK(&steam->unregister_work2, steam_work_unregister_cb2);
 
 	/*
 	 * With the real steam controller interface, do not connect hidraw.
@@ -1314,6 +1310,7 @@ err_cancel_work:
 	cancel_delayed_work_sync(&steam->mode_switch);
 	cancel_work_sync(&steam->rumble_work);
 	cancel_work_sync(&steam->unregister_work);
+	cancel_work_sync(&steam->unregister_work2);
 
 	return ret;
 }
@@ -1330,7 +1327,6 @@ static void steam_remove(struct hid_devi
 	cancel_delayed_work_sync(&steam->mode_switch);
 	cancel_work_sync(&steam->work_connect);
 	cancel_work_sync(&steam->rumble_work);
-	cancel_work_sync(&steam->unregister_work);
 	hid_destroy_device(steam->client_hdev);
 	steam->client_hdev = NULL;
 	steam->client_opened = 0;
@@ -1340,6 +1336,8 @@ static void steam_remove(struct hid_devi
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
 	steam_unregister(steam);
+	flush_work(&steam->unregister_work);
+	flush_work(&steam->unregister_work2);
 }
 
 static void steam_do_connect_event(struct steam_device *steam, bool connected)
--