7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fan Wu commit 189b9dc8c96ec9486482f27c1372b04a7152175e upstream. brcmuart_handle_irq() starts priv->hrt to work around a receive-timeout quirk of the 8250 core when hardware flow control is enabled; the timer callback brcmuart_hrtimer_func() dereferences priv. brcmuart_remove() cancels the hrtimer before it unregisters the port, so a receive-timeout interrupt that arrives in between re-arms the timer. After devm frees priv, the callback runs on freed memory. Unregister the port before cancelling the hrtimer. serial8250_unregister_port() shuts the port down and frees its IRQ, so brcmuart_handle_irq() can no longer restart the timer, and the final hrtimer_cancel() drains any timer that was armed before or during the unregister. This issue was found by an in-house static analysis tool. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Cc: stable@kernel.org Assisted-by: Codex:gpt-5.6 Co-developed-by: Song Li Signed-off-by: Song Li Signed-off-by: Fan Wu Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20260909084002.686911-1-fanwu01@zju.edu.cn Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_bcm7271.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/8250/8250_bcm7271.c +++ b/drivers/tty/serial/8250/8250_bcm7271.c @@ -1123,8 +1123,8 @@ static void brcmuart_remove(struct platf struct brcmuart_priv *priv = platform_get_drvdata(pdev); debugfs_remove_recursive(priv->debugfs_dir); - hrtimer_cancel(&priv->hrt); serial8250_unregister_port(priv->line); + hrtimer_cancel(&priv->hrt); brcmuart_free_bufs(&pdev->dev, priv); if (priv->dma_enabled) brcmuart_arbitration(priv, 0);