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=1793829588; b=TZgYJpJZydbp2603dZ5f7/hUcWbu9n1FAcjuTC8sX/7dIbPLYFWAfMAIBaB+3hoL/Eo0 CQ+WYbJ79B8tWG3mv1hVq+qWKHsvGkO4OgdXxZ57xoVVTrQdZzWgrVbvuWXBXAZAmQ6U2 KfOhD3/NiAuzY+gumrlmWkmfquFHMGn7k3dQvcGP9AwZ9/Moys2sN1uX9EGltDvG9Q5FU P4eo4BNmmO06aunKgrW3xUR1we41MXmrcecrEc7W/BjKZq9RNylfb6LD7x3j47ifoTzi8 FNJ48u9SP7S/KIkQohTST6vftYLGubctv+CId/KA+t02tVPuq5oDtP0kNpKNHru9UMA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793829588; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=4hX1ECn4Gz1bgo18Ti5ckwohdlX4qywwuLnsm88YT88=; b=bkIf2UHTWPxAG6BEAL+zWFmtGAiKGXtWY42g+E6IyGivofDUv6gvdO+XA+6mzdVEUEgg ri7050yH37wXYGiaJq/0XcL142941Sjkldn3RK4jWJ4ph5sQY6//lEuIlYxuYVNFg4iIT F1MoR4WqLSlXEtpv/gJXRFf7w+UvbbzW2Z5lAhvszn47GIgdEPCzm6aiIJku2GxMzK4Ji mM/TrZI7EBVrRprdSJN27KZ/04coYrU3lgyd/Lr3IXYRudaSwPRVi5qVvFxOq+JZJjmbH 35jy5dXIk1+wrZqU4g7YjzvA3npHH/zxA53FVLty5DeLU2oNSyIH//5K1FUxrCxtz0w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="ugcJHhv/"; 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 3F385607527E; Wed, 4 Nov 2026 21:59:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=ugcJHhv/ Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEE7F1F00A18; Wed, 4 Nov 2026 21:59:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793829588; bh=4hX1ECn4Gz1bgo18Ti5ckwohdlX4qywwuLnsm88YT88=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ugcJHhv/OmTLEtjp6nn+eYzzYYQ6oIN+xzJ0lY1hoKXoHB+fyJXOfeu+0I9GeIt6K PAR0iro6KKB6dKVB2DFyy5XpqF9IcfDOavPURmJ9umraHyKbBmYgxMyRp0J3Tm7Psp xczptKq9IQVOzOVSL+Qr7qWDh7VdAR9jUylgSHCw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ian Abbott , Sasha Levin Subject: [PATCH 6.18 0181/1005] comedi: dt2811: Fix sanity check in interrupt handler Date: Wed, 4 Nov 2026 15:58:34 -0500 Message-ID: <20261104211048.852842565@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ian Abbott [ Upstream commit 8dda63825752ab19fcbc2a19ecab91d128112415 ] The driver requests an interrupt handler for the device, after setting device registers to disable interrupt generation. The interrupt handler should not be called prematurely unless the user-configured I/O port base address and/or IRQ number are incorrect or the hardware is bad. For safety, the interrupt handler checks the dev->attached flag to ensure the device is fully set up, but it currently does that after dereferencing dev->read_subdev, which may be NULL if dev->attached is false. Move the check to avoid the possible null pointer dereference. Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260618102949.26607-4-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/comedi/drivers/dt2811.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/comedi/drivers/dt2811.c b/drivers/comedi/drivers/dt2811.c index dbb9f38da2898..c2ec5e4fb689f 100644 --- a/drivers/comedi/drivers/dt2811.c +++ b/drivers/comedi/drivers/dt2811.c @@ -193,13 +193,16 @@ static irqreturn_t dt2811_interrupt(int irq, void *d) { struct comedi_device *dev = d; struct comedi_subdevice *s = dev->read_subdev; - struct comedi_async *async = s->async; - struct comedi_cmd *cmd = &async->cmd; + struct comedi_async *async; + struct comedi_cmd *cmd; unsigned int status; if (!dev->attached) return IRQ_NONE; + async = s->async; + cmd = &async->cmd; + status = inb(dev->iobase + DT2811_ADCSR_REG); if (status & DT2811_ADCSR_ADERROR) { -- 2.53.0