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=1794047666; b=VRWW6KLnPo29tbjCLM5TTcVh8urxsaWz8nghId2zA1prNo5GiniVULbGadMn2056pCsv 74lgfbJ1tq2Th7WyajSZ3ikkjEUA6sDpLVqgj6sumyi3YIsh97mG0a8E/QjSUuHm0MU8y HYFYWFVQW3D7fpyuB/7SOY3a7s9KoHOmrM2RnxVcJc0pctDA2hTpb29OdrrC37dFp9dMB Y0nX5vdCZ90VeJqc3sBGGjhXqwF17f16+ZRoNdNpoK3+EWFQiULxkchFWS8Y4M/NaVol0 cb8ese0HP+bWS1Ouk5E2+ahjtzG1g8NW/LNTj5lBhgQgxsa8gTN+eWK+61ejdLnmPOA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047666; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=ElnQWFHa71IztobyXNzCucAdh6xi5tFV+8hHsaPVEwA=; b=cebhguv+WiJnKC9pXfxG9Ibn+Qi3es87x50XmtSHXMb3jeFxS5vxnBv2HgedSpK9PnXY HcGtPuFT+fPcxwbnqAVbhsNNXOC3Isbrc/i4GpYaEVblxXdeFSKrSbvDi4BpxFOWI+ePY l9CURHrRMedgEIs4ELbFCiYApx7+jnOvPAoOWWMP6HDltx+uzdbYE6WaPQPe1OUSd2Fr3 rqVKetrwFI7rxvtwYzvjdCcdt0mMnXpMBuRdwFqznTGjKtoCXf2X0GIb0bUBbUhIMbIFG wSIMZQxucZasR8bZXq78Jl5iH1cjvXAUHwJ0TWSb1M//wiXb4D+fvqSOLxCJp1YqPsQ== 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=dyknddEr; 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 CEA83606A326 for ; Sat, 7 Nov 2026 10:34:25 +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=dyknddEr Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F0491F0089F; Sat, 7 Nov 2026 10:34:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047665; bh=ElnQWFHa71IztobyXNzCucAdh6xi5tFV+8hHsaPVEwA=; h=From:To:Cc:Subject:Date; b=dyknddErTyJBdV0ENuNsVcfX3WEw0BXKew3QUXgFcGfAbkgp5x/tBXa3K2c5JMF6a U+aXwj3DnM+TFhYjWdG44L2+j56B2+e1mZF0Q6UIvVjCU7Pba/0D2yrX6Jk4aNWMVr myK96ezFTomoBjfONGohxVWOFi990XtiMx1LaUZQtBlz+WYiusy5u+lCiEF3e0nR6o UNPyC4HGWj4WVUyiItsqi68DJ3sF8eTnmKCOgsvq4E/MwZ9g3n8G3ReNIDzNNSmuW8 pMt/kQQ9skO0vYzfCvLFj3RMR2u48t0ykupJyfKNolOaKp1PLsRa4SOssojbm5WvJ7 5TWnxEzAaiY6g== From: Sasha Levin To: jirislaby@kernel.org, gregkh@linuxfoundation.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] serial: 8250_exar: store the GPIO platform device in struct exar8250" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:34:24 -0500 Message-ID: <20261107053424-failed-6.6-33d337816e00@kernel.org> X-Mailer: git-send-email 2.53.0 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 33d337816e00994daaf670243186d9e537ee090d # git commit -s git send-email --to '' --in-reply-to '20261107053424-failed-6.6-33d337816e00@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 33d337816e00994daaf670243186d9e537ee090d Mon Sep 17 00:00:00 2001 From: "Jiri Slaby (SUSE)" Date: Tue, 13 Oct 2026 08:48:48 +0200 Subject: [PATCH] serial: 8250_exar: store the GPIO platform device in struct exar8250 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 --- 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 ad2e5841fbf69..29b2a29ab6f37 100644 --- a/drivers/tty/serial/8250/8250_exar.c +++ b/drivers/tty/serial/8250/8250_exar.c @@ -231,8 +231,9 @@ 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); }; /** @@ -256,6 +257,7 @@ struct exar8250 { struct exar8250_board *board; struct eeprom_93cx6 eeprom; void __iomem *virt; + struct platform_device *gpio; int line[]; }; @@ -1167,22 +1169,21 @@ 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 sealevel_rs485_config(struct uart_port *port, struct ktermios *termios, @@ -1279,8 +1280,9 @@ 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; @@ -1289,8 +1291,7 @@ 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; } @@ -1367,7 +1368,7 @@ 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; @@ -1377,9 +1378,8 @@ 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