From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EA19D406834; Mon, 7 Sep 2026 06:45:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788763502; cv=none; b=Kb9GZvgJtlNANUKReUnRZrlc2lR0E3r8drURMiB3Kthw2xmkEhrXpzL/hsHIUhSObfx1IahKCw9absf8pueDxynDHfe63OMcS4VoOwwCX8nyy/D2BT7NsWt9motD4URdBeq/SJrEYt7wJRiuCEBbYb6pr7vIf1aSWo+Glo0+Ctc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788763502; c=relaxed/simple; bh=x66OTmE+2GoMrDOkCx9Gp+1mdgvBmhCVWJZ3x+2aW8g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q5CyAGfrCUKbIrZZsS0DaVVx4hy1pFuhdN5f860Rr8wfDzz11hYlPOSOkMqrx9AmoEJZDCd0ivlZb94UJEzk0fQM++Oey5sDsNZJ006dVv68QZE6Ehbfjggos2W4RFFzAwFlDK6E0qKGrWVzfIKN+3smwYV6wf5SadSSX44YoLY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DZchNzdW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DZchNzdW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94ED81F00A3D; Mon, 7 Sep 2026 06:45:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788763500; bh=uKkl+WCnZ3v7/vev4Fux3tOv4sXrORFW6CikZ1muEWY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=DZchNzdWPSIUMz5EDTVju2UauvqwvKBgOZwgWylIvokg8chfX4imLvTbQ0D0sswBM VjzM4gd9j61kqcJZ3b1vf2nHuuAGHAqb7VtcjcUdO4Hrfjs7ukXQja01HF0CoJcd8t YVJHQbvz2w68cbA4+clbvgfjilxAP7PFpEeMhE6NneuzvogNZBzHZJ3DPh3gqX+9hx GP0EzGyDbywa/tRRHz14Nggtc5/ZtqJ0y7EBUn1N4jDoGV4nq6Cf1Ss/tNW93ovJmF kgjFnDro1RNiVALjzNMMLRYjpuJsuDd3EK4Z2QM9rqmMI2KL/UxYxbNw2RUS17GQGc WCaT5NK6PqNyw== Received: from johan by xi.lan with local (Exim 4.99.4) (envelope-from ) id 1x3T69-00000000OC8-3nyj; Mon, 07 Sep 2026 08:44:57 +0200 From: Johan Hovold To: Greg Kroah-Hartman , Jiri Slaby Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , sashiko-bot@kernel.org, stable@vger.kernel.org Subject: [PATCH v3 3/4] serial: fix TIOCMIWAIT race Date: Mon, 7 Sep 2026 08:44:17 +0200 Message-ID: <20260907064418.92953-4-johan@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260907064418.92953-1-johan@kernel.org> References: <20260907064418.92953-1-johan@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The task state must be updated before checking the wakeup condition to avoid missing a racing modem status update. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: sashiko-bot@kernel.org Link: https://lore.kernel.org/r/20260904115542.E20D11F00A3D@smtp.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold --- drivers/tty/serial/serial_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 4213fa3dc988..c2c2c8fe1a4c 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1230,12 +1230,12 @@ static int uart_wait_modem_status(struct tty_struct *tty, struct uart_state *sta add_wait_queue(&port->delta_msr_wait, &wait); for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + uart_port_lock_irq(uport); memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); uart_port_unlock_irq(uport); - set_current_state(TASK_INTERRUPTIBLE); - if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || -- 2.55.0