From nobody Wed Sep 3 06:42:32 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74E06FA3750 for ; Mon, 24 Oct 2022 12:35:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234720AbiJXMfr (ORCPT ); Mon, 24 Oct 2022 08:35:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234269AbiJXM3y (ORCPT ); Mon, 24 Oct 2022 08:29:54 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 524B7CE16; Mon, 24 Oct 2022 05:03:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6CA10B8118A; Mon, 24 Oct 2022 12:01:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB52DC433C1; Mon, 24 Oct 2022 12:01:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666612870; bh=pMoeHjQy/ObZ8+wueUd63+e+HB70jsgojMHn/4MTjLQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qLFw5H/gNC8HsFyt409AxqOunqP7Vj7NI2YnHCxyqOEDxui1+qw2tLohJ906PSZse PodRr9x/wfrvu1OZPIMvNqs89Y6oK0t3lmriFbWI+rQ1vi4e7aaRjpJJNbWCDmeJoF T4BHOKGAJ6jPxklOIr3sln2y8+QAb/ZbSgWt2eoI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Nuno=20S=C3=A1?= , Jonathan Cameron , Sasha Levin Subject: [PATCH 4.19 119/229] iio: inkern: only release the device node when done with it Date: Mon, 24 Oct 2022 13:30:38 +0200 Message-Id: <20221024113002.840760071@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nuno S=C3=A1 [ Upstream commit 79c3e84874c7d14f04ad58313b64955a0d2e9437 ] 'of_node_put()' can potentially release the memory pointed to by 'iiospec.np' which would leave us with an invalid pointer (and we would still pass it in 'of_xlate()'). Note that it is not guaranteed for the of_node lifespan to be attached to the device (to which is attached) lifespan so that there is (even though very unlikely) the possibility for the node to be freed while the device is still around. Thus, as there are indeed some of_xlate users which do access the node, a race is indeed possible. As such, we can only release the node after we are done with it. Fixes: 17d82b47a215d ("iio: Add OF support") Signed-off-by: Nuno S=C3=A1 Link: https://lore.kernel.org/r/20220715122903.332535-2-nuno.sa@analog.com Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/inkern.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index a8ccc6e5a773..5108b0504616 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -139,9 +139,10 @@ static int __of_iio_channel_get(struct iio_channel *ch= annel, =20 idev =3D bus_find_device(&iio_bus_type, NULL, iiospec.np, iio_dev_node_match); - of_node_put(iiospec.np); - if (idev =3D=3D NULL) + if (idev =3D=3D NULL) { + of_node_put(iiospec.np); return -EPROBE_DEFER; + } =20 indio_dev =3D dev_to_iio_dev(idev); channel->indio_dev =3D indio_dev; @@ -149,6 +150,7 @@ static int __of_iio_channel_get(struct iio_channel *cha= nnel, index =3D indio_dev->info->of_xlate(indio_dev, &iiospec); else index =3D __of_iio_simple_xlate(indio_dev, &iiospec); + of_node_put(iiospec.np); if (index < 0) goto err_put; channel->channel =3D &indio_dev->channels[index]; --=20 2.35.1