[PATCH 6.12 114/460] usb: renesas_usbhs: fix use-after-free in ISR during device removal

Greg Kroah-Hartman
2026-03-23T14:17:51Z

6.12-stable review patch. If anyone has any objections, please let me know.

------------------

From: Fan Wu <fanwu01@zju.edu.cn>

commit 3cbc242b88c607f55da3d0d0d336b49bf1e20412 upstream.

In usbhs_remove(), the driver frees resources (including the pipe array)
while the interrupt handler (usbhs_interrupt) is still registered. If an
interrupt fires after usbhs_pipe_remove() but before the driver is fully
unbound, the ISR may access freed memory, causing a use-after-free.

Fix this by calling devm_free_irq() before freeing resources. This ensures
the interrupt handler is both disabled and synchronized (waits for any
running ISR to complete) before usbhs_pipe_remove() is called.

Fixes: f1407d5c6624 ("usb: renesas_usbhs: Add Renesas USBHS common code")
Cc: stable <stable@kernel.org>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260303073344.34577-1-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/renesas_usbhs/common.c | 9 +++++++++
1 file changed, 9 insertions(+)

--- a/drivers/usb/renesas_usbhs/common.c
+++ b/drivers/usb/renesas_usbhs/common.c
@@ -811,6 +811,15 @@ static void usbhs_remove(struct platform

usbhs_platform_call(priv, hardware_exit, pdev);
reset_control_assert(priv->rsts);
+
+ /*
+ * Explicitly free the IRQ to ensure the interrupt handler is
+ * disabled and synchronized before freeing resources.
+ * devm_free_irq() calls free_irq() which waits for any running
+ * ISR to complete, preventing UAF.
+ */
+ devm_free_irq(&pdev->dev, priv->irq, priv);
+
usbhs_mod_remove(priv);
usbhs_fifo_remove(priv);
usbhs_pipe_remove(priv);