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=1794060727; b=vIebgARmXBpaaCu5ATFXxAXXEYwaMGmXcseYGLBxr3DoweUtnM4rJCRbNemui+SOQLpb bkMk3tEOxyh7LXyFZ5LSsSTF5GRus1eKdM/s2gfQVKGickz8yNyz71twuCIpR31rDXBu8 /+oJ09OgpXD7UoVifdydBJM6kdVG/AuBo4fodO6c+G6/9NQDMeSJJu9gXgw752xttw/qF yJgEwOlqwS95Xm3so2K/T01Vqgc32GjxLOA5vwj4/uZZwlZhbSZccs6wP6DLRKD1wrMBt 038g8GXmG4PvmGnPBbqOZca6CtnrL4s23hxU1RijQnjAuXu1UW70NTENKlDbWgmbDSw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794060727; 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=LkxkwhK6ml15SiGYODO4v9hWHjKaRl25GiVx+f7noss=; b=UYkl+tsqES5v9BR+kr196Acg75Fu0gSZ9jYNArhNZWRwI2ZzYiRoe1LbIQoJv648WTxA 7gad33W5R3Md7th3O5NxKhNRp4R0pcjblazsO+HUPo7zmIwn6pfIyLLFOAGaPH7PzKcdb W/adv1NF2JbcitHFCjoeeZVbpWkIH6WvCW+LvrZ5llBGeitSDOJoiVuMxzMPIPXfLYRBF vrUEcFU0nJK8fGZiyJGmc4su7q3P099xWWPM+6IEK2ES0yKwF7Rv4vWIdIeEesB6NuWRA H86zh+o6AHQZGBUmQhdzlHzyIvZsaRN+P8hMWqwaW5bQCRjtM9Adm/uILgUYm9nBULQ== 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=zB+BGmpu; 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 96F51606A32C; Sat, 7 Nov 2026 14:12:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=zB+BGmpu Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4282B1F008A1; Sat, 7 Nov 2026 14:12:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794060727; bh=LkxkwhK6ml15SiGYODO4v9hWHjKaRl25GiVx+f7noss=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=zB+BGmpuaQtGkdoc6hB+ljntKiby4Kd55THBQviWVEohShk77UygiYTtTDDvXKCD/ Y8Q81SWQIU3UjVLQre9WckA2Kp9I5fy6meaCDxZV80hzPvjMUmyfocVS/vEPRbNPld ITAgV4af00RkLC3k16ApRajE4ZG24d6pvzr9pwfE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ian Abbott , Sasha Levin Subject: [PATCH 6.12 0147/1536] comedi: quatech_daqp_cs: Fix sanity check in interrupt handler Date: Sat, 7 Nov 2026 08:36:03 -0500 Message-ID: <20261107135001.818159936@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ian Abbott [ Upstream commit 1bc9538df6be8dac8727179d8bcc0d880648361b ] The driver requests an interrupt handler for the device before it is fully set up. 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 the dev->read_dev pointer 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/20260618102949.26607-12-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/comedi/drivers/quatech_daqp_cs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/comedi/drivers/quatech_daqp_cs.c b/drivers/comedi/drivers/quatech_daqp_cs.c index 2a76c75c513b8..d5e3e213e233b 100644 --- a/drivers/comedi/drivers/quatech_daqp_cs.c +++ b/drivers/comedi/drivers/quatech_daqp_cs.c @@ -211,13 +211,15 @@ static irqreturn_t daqp_interrupt(int irq, void *dev_id) { struct comedi_device *dev = dev_id; struct comedi_subdevice *s = dev->read_subdev; - struct comedi_cmd *cmd = &s->async->cmd; + struct comedi_cmd *cmd; int loop_limit = 10000; int status; if (!dev->attached) return IRQ_NONE; + cmd = &s->async->cmd; + status = inb(dev->iobase + DAQP_STATUS_REG); if (!(status & DAQP_STATUS_EVENTS)) return IRQ_NONE; -- 2.53.0