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=1794060730; b=406KkUBTukUB4ii+ImNmDg4DoDbApoZWU/suyTMz5YWDxZP3jbb/ZkD8JZQ5NA8p3Dwz pXYvDLzjYjL1uMpQYmYoNuyxMS6KzfYJiK1DUqVT1WveFst/WfHsfvfQRrJEMdBgASakt Ck/bm0HpozqtKDt1xNmoKKCoeWKCIX+zCBwqksyPiJlNcB1HpCPa5p+GSsTNtsG735hVi /WQEkoZsnghFt95t4W7l6FmMuroRgv8lm5UxVhS/eogo3OshwLFJB7QP8D8VNsJYGdYjP 8eTebz0RkLF/8Cdyw3f/lBeuGf9uYul8KTB4+fZH0kszLlYfcgUa3jbXAh/L83JYaHw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794060730; 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=9t2buXN3ky8LF+yNzfVEDFtKtmWKalH7DggeERryT9w=; b=KUgTmODwRYjOaoul0MlJdSb2DGaiRzLcmTOOqqk991jUNfX8CSplvp9VgloDSCFzfkFJ BWqX1PPDh3oI5vueDUxOllvhpZuc9+ldEmyZrK6k1kNuJbjcT0O0V2O6368vUuzECIh0P ty4+ELNoV5pmA5nm2JpLk/IoOmHYXyowridEj1M7dkd6KkVYLx5xOxgxGU1hYpZgTPMyr WJFw99UgBiXvRlhQHMlURHWpQV4JU4QI2VaEJKfARXayk+HTyuFUxBJEkwFYbl3FtY1OF n1g9gbQYIoxj+SzdqlvWWakORZQDeRIUOx9xcrMHwgvsp3OYzbki90B0N6i2ocuyVLA== 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=jAAMd18A; 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 1BAF7606A338; Sat, 7 Nov 2026 14:12:10 +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=jAAMd18A Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA5B91F008A1; Sat, 7 Nov 2026 14:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794060730; bh=9t2buXN3ky8LF+yNzfVEDFtKtmWKalH7DggeERryT9w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jAAMd18AvnJDOW+eFPGgNi75UWOYNbeUXZ51/AbrGuRqPoMUBsI5ky0+IKnxS95Z5 0CTfi6/P1j1krwjI08l6yep2MXbR02+dyGan8u9UFf7PAFO50NFyxwxl2fHXBKdf1j Ww4MC/rTImQjszE/ZxszIHXTBzXi9cDrJdGlo7E4= 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 0149/1536] comedi: dt2811: Fix sanity check in interrupt handler Date: Sat, 7 Nov 2026 08:36:05 -0500 Message-ID: <20261107135001.870979961@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 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