From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87BCF79DC; Sat, 30 Dec 2023 12:09:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="m0WuPKsR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11E62C433C9; Sat, 30 Dec 2023 12:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1703938188; bh=O1h+StoktARVjPQjYbWBr5QGTgOAu4iS92+V2qsYecE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m0WuPKsRAd7pq8x5FQbfcX26Ji6Ls9psGiFuXtE0iWun+qAH31IVivoi+hPlbC+5g 749tIeyNU0GwHct+vBTJnGF62mlV7GsYm6FOb7aZwGeox2Ly1OvenzdA+YvkfktRZ0 oOgwe3ytc7Hr71Oqs53Hs62Ddd+J5LpyFag+xy+M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Lechner , Nuno Sa , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 6.1 061/112] iio: triggered-buffer: prevent possible freeing of wrong buffer Date: Sat, 30 Dec 2023 11:59:34 +0000 Message-ID: <20231230115808.655408509@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231230115806.714618407@linuxfoundation.org> References: <20231230115806.714618407@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Lechner commit bce61476dc82f114e24e9c2e11fb064781ec563c upstream. Commit ee708e6baacd ("iio: buffer: introduce support for attaching more IIO buffers") introduced support for multiple buffers per indio_dev but left indio_dev->buffer for a few legacy use cases. In the case of the triggered buffer, iio_triggered_buffer_cleanup() still assumes that indio_dev->buffer points to the buffer allocated by iio_triggered_buffer_setup_ext(). However, since iio_triggered_buffer_setup_ext() now calls iio_device_attach_buffer() to attach the buffer, indio_dev->buffer will only point to the buffer allocated by iio_device_attach_buffer() if it the first buffer attached. This adds a check to make sure that no other buffer has been attached yet to ensure that indio_dev->buffer will be assigned when iio_device_attach_buffer() is called. As per discussion in the review thread, we may want to deal with multiple triggers per device, but this is a fix for the issue in the meantime and any such support would be unlikely to be suitable for a backport. Fixes: ee708e6baacd ("iio: buffer: introduce support for attaching more IIO buffers") Signed-off-by: David Lechner Acked-by: Nuno Sa Link: https://lore.kernel.org/r/20231031210521.1661552-1-dlechner@baylibre.com Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/buffer/industrialio-triggered-buffer.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/iio/buffer/industrialio-triggered-buffer.c +++ b/drivers/iio/buffer/industrialio-triggered-buffer.c @@ -46,6 +46,16 @@ int iio_triggered_buffer_setup_ext(struc struct iio_buffer *buffer; int ret; + /* + * iio_triggered_buffer_cleanup() assumes that the buffer allocated here + * is assigned to indio_dev->buffer but this is only the case if this + * function is the first caller to iio_device_attach_buffer(). If + * indio_dev->buffer is already set then we can't proceed otherwise the + * cleanup function will try to free a buffer that was not allocated here. + */ + if (indio_dev->buffer) + return -EADDRINUSE; + buffer = iio_kfifo_allocate(); if (!buffer) { ret = -ENOMEM;