From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794343375; b=aLUCLRgFwDYMBQaQY8qPjIVWLSBk8TmzIhyuVDz89XWlYFNv6abgynDEwkG3zfleRxZX 5HU6tD90y4+5XSeh01MamB3pek0jVn7Bs25hFevJttdez7RJKCdvsN568o3ALKp2XJ433 j9xoUO7wXF2AvLjzO6+T5DSHUzEgnppTX1NItYWhLYyoIdbDOrkeLYV4AczdXfcnUsDqR hoqRLjZXBrIrRx/WPdVrSgTq8qJkeBqNtl/QiJrptyWV8uLQXk3066vaRpy67EhihJ64m XD74a7VtZAEQ809cdhJvGkFev1gB2Rk8Je7Uc0ArGO/UCsBIwCWJcSinEQoiVB6ThGA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794343375; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=becI3p+sQNx/eEVjlWgUndzwQKXlj80fI+ex6CDMkM8=; b=RnpNDdBnerFIVn1V1FvfHr+MRga3INTOhz1XfAfuWOO5FIG3f3jUe1rwT3g7+JR4tF0v h/ex97oUqe3T7abxV/fsWuF++/x62tbS1U8QQ22LW6jV1rk9eBghOelWD9MJtfdLNaC5/ UWH5KRLyGh/pB32Qfj2NosDcxlLVAi4yKP7QN8VOYfuwlHYIqs8afpaITTHWXRiEcT5KJ Ba0eI/Ct+YPidbvBAyavqJO8r1Csx8NGN4P3VAXjLEk0ygvpaOWFIlzkLWKunOWRjEdLW gbAf9gQZCMC++BNJKw6XG3wTj/PQtZ408VoNmFrivt8bMNoccTJciDWgTJ6WRN4vtVg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Jf2GJrQP; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F7F7606A330 for ; Tue, 10 Nov 2026 20:42:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Jf2GJrQP Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8065C1F008A1; Tue, 10 Nov 2026 20:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794343375; bh=becI3p+sQNx/eEVjlWgUndzwQKXlj80fI+ex6CDMkM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Jf2GJrQPo4fGWb+hKORpAIAoD/v/IcGAv3ZM/lVXTGEx8ZHgu+Oj57CLTtXFJjofY YFfonz1LfWiSHsC8aSHyiSnVwtB6XtBcZXC2MSYOyC5/Gjgna2eJ+hbC8Vhr8qCjKy tfOr/xDx1pgAWiVJGoHe4G29cjb4S414+mm4l0fEt0GzUAT6/OaBLHtnLBLxUCVHFA I2Mx4v/L0pg+NWj6/cM5nTkKaCVV1F8yBVw0Nskpru1OWFlEwbTx80yO9tiIfoSatN p8gGrjavDFt5vOnK96O7CNTII9+AIWmQexGYxfLY3XrTcwLNYtffgXiv5applkhIc2 UyNzDaHsqUK9A== From: Sasha Levin To: stable@vger.kernel.org Cc: "Jiri Slaby (SUSE)" , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.1.y 4/4] serial: 8250_exar: store the GPIO platform device in struct exar8250 Date: Tue, 10 Nov 2026 15:42:51 -0500 Message-ID: <20261110204132.3796786-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261110204132.3796786-1-sashal@kernel.org> References: <20261107054802-failed-6.1-33d337816e00@kernel.org> <20261110204132.3796786-1-sashal@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Jiri Slaby (SUSE)" [ Upstream commit 33d337816e00994daaf670243186d9e537ee090d ] The GPIO platform device is registered via platform->register_gpio() when port 0 is being set up. It is stored to port->port.private_data of the on-stack uart template (and from there it is copied into every registered port). pci_xr17v35x_exit() then fetches it back by serial8250_get_port(priv->line[0]). But port 0 does not have to exist at that point. If serial8250_register_8250_port() fails for port 0, priv->line[0] holds a negative error code. The probe still succeeds (it only breaks the loop), so on unbind, priv->line[0] (a negative value) is passed to serial8250_get_port(). The GPIO device is never unregistered and a bogus port is accessed. The same problem would also occur after the planned conversion of serial8250_register_8250_port() to return a uart port instead of a line. As Sashiko pointed out in that case: If board->setup() fails for the first port (i=0) in exar_pci_probe(), priv->uport[0] remains NULL. If serial8250_register_8250_port() fails, it returns an ERR_PTR. In either case, the loop breaks and probe returns success. When the device is later unbound, pci_xr17v35x_exit() unconditionally passes priv->uport[0] to platform->unregister_gpio(), which will dereference it without checking for validity. The GPIO device belongs to the PCI device, not to any particular port. So store it in a new struct exar8250::gpio member. Pass priv to both ->register_gpio() and ->unregister_gpio(), so that pci_xr17v35x_exit() does not need to look up any port at all. Signed-off-by: Jiri Slaby (SUSE) Fixes: d0aeaa83f0b0 ("serial: exar: split out the exar code from 8250_pci") Link: https://lore.kernel.org/all/sashiko-outbox-166269@kernel.org/ Assisted-by: LLM Cc: stable@vger.kernel.org Link: https://patch.msgid.link/03a8b5c71614fc672fef1e55c083bda6c73b5bf3.1791873876.git.jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_exar.c | 36 ++++++++++++++--------------- 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c index 9326a7bd4e2a1..7645cbf6b4d2e 100644 --- a/drivers/tty/serial/8250/8250_exar.c +++ b/drivers/tty/serial/8250/8250_exar.c @@ -169,8 +169,9 @@ struct exar8250_platform { int (*rs485_config)(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485); const struct serial_rs485 *rs485_supported; - int (*register_gpio)(struct pci_dev *pcidev, struct uart_8250_port *port); - void (*unregister_gpio)(struct uart_8250_port *port); + int (*register_gpio)(struct exar8250 *priv, struct pci_dev *pcidev, + struct uart_8250_port *port); + void (*unregister_gpio)(struct exar8250 *priv); }; /** @@ -194,6 +195,7 @@ struct exar8250 { unsigned int nr; struct exar8250_board *board; void __iomem *virt; + struct platform_device *gpio; int line[]; }; @@ -448,22 +450,21 @@ static const struct software_node exar_gpio_node = { .properties = exar_gpio_properties, }; -static int xr17v35x_register_gpio(struct pci_dev *pcidev, struct uart_8250_port *port) +static int xr17v35x_register_gpio(struct exar8250 *priv, struct pci_dev *pcidev, + struct uart_8250_port *port) { if (pcidev->vendor == PCI_VENDOR_ID_EXAR) - port->port.private_data = - __xr17v35x_register_gpio(pcidev, &exar_gpio_node); + priv->gpio = __xr17v35x_register_gpio(pcidev, &exar_gpio_node); return 0; } -static void xr17v35x_unregister_gpio(struct uart_8250_port *port) +static void xr17v35x_unregister_gpio(struct exar8250 *priv) { - if (!port->port.private_data) - return; - - __xr17v35x_unregister_gpio(port->port.private_data); - port->port.private_data = NULL; + if (priv->gpio) { + __xr17v35x_unregister_gpio(priv->gpio); + priv->gpio = NULL; + } } static int generic_rs485_config(struct uart_port *port, struct ktermios *termios, @@ -546,8 +547,9 @@ static const struct software_node iot2040_gpio_node = { .properties = iot2040_gpio_properties, }; -static int iot2040_register_gpio(struct pci_dev *pcidev, - struct uart_8250_port *port) +static int iot2040_register_gpio(struct exar8250 *priv, + struct pci_dev *pcidev, + struct uart_8250_port *port) { u8 __iomem *p = port->port.membase; @@ -556,8 +558,7 @@ static int iot2040_register_gpio(struct pci_dev *pcidev, writeb(IOT2040_UARTS_ENABLE, p + UART_EXAR_MPIOLVL_15_8); writeb(IOT2040_UARTS_GPIO_HI_MODE, p + UART_EXAR_MPIOSEL_15_8); - port->port.private_data = - __xr17v35x_register_gpio(pcidev, &iot2040_gpio_node); + priv->gpio = __xr17v35x_register_gpio(pcidev, &iot2040_gpio_node); return 0; } @@ -631,7 +632,7 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev, /* Setup Multipurpose Input/Output pins. */ setup_gpio(pcidev, p); - ret = platform->register_gpio(pcidev, port); + ret = platform->register_gpio(priv, pcidev, port); } return ret; @@ -641,9 +642,8 @@ static void pci_xr17v35x_exit(struct pci_dev *pcidev) { const struct exar8250_platform *platform = exar_get_platform(); struct exar8250 *priv = pci_get_drvdata(pcidev); - struct uart_8250_port *port = serial8250_get_port(priv->line[0]); - platform->unregister_gpio(port); + platform->unregister_gpio(priv); } static inline void exar_misc_clear(struct exar8250 *priv) -- 2.53.0