From nobody Wed Sep 10 09:18:12 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 773D8EE4998 for ; Fri, 18 Aug 2023 20:42:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380033AbjHRUlw (ORCPT ); Fri, 18 Aug 2023 16:41:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1380001AbjHRUlS (ORCPT ); Fri, 18 Aug 2023 16:41:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DE913C3C; Fri, 18 Aug 2023 13:41:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0BCBE622A0; Fri, 18 Aug 2023 20:41:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A43C9C433C7; Fri, 18 Aug 2023 20:41:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692391276; bh=3y9hbinbB0yISDHYlIuRC1XY5FlDSwxU7pK4HWAm7fU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=V5/0aS859lKdC/BbEGOtLiiZZZSkVoZ82wV/Vlc76USAGKEqBOP6maRONeTYA7MUO SVAOIHd4D+fcj2P10GNV+h/zkzIW/r8oeZDN8zZEDmtpblB04a4jclOSleW9IhmOMN xP5ZErYJOh3/Pu/btYHFG4hg5HSXpx53jMvdGzTkms/MKtOD/6UliIxAm5cfgSxEXU 83E21siT9DWUa/MO1SHQvCTLU5zqYv+kDWtWm90IFqKGGTHsU6HZNVEaR/Pb7jrKSi /1UyPytTsVCGKPTzpeZTtfRRLTq5aTZX0pdMu9KEVq3TaCmIE63NIpGwF2Es71gQ1j almBs2MThNiyQ== Received: (nullmailer pid 545144 invoked by uid 1000); Fri, 18 Aug 2023 20:41:06 -0000 From: Rob Herring Date: Fri, 18 Aug 2023 15:40:59 -0500 Subject: [PATCH v3 4/6] of: dynamic: Fix race in getting old property when updating property MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20230801-dt-changeset-fixes-v3-4-5f0410e007dd@kernel.org> References: <20230801-dt-changeset-fixes-v3-0-5f0410e007dd@kernel.org> In-Reply-To: <20230801-dt-changeset-fixes-v3-0-5f0410e007dd@kernel.org> To: Frank Rowand , "Enrico Weigelt, metux IT consult" , "Rafael J. Wysocki" , Sakari Ailus , Petr Mladek , Andy Shevchenko , Geert Uytterhoeven Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org X-Mailer: b4 0.13-dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org __of_update_property() returns the existing property if there is one, but that value is never added to the changeset. Updates work because the existing property is also retrieved in of_changeset_action(), but that is racy as of_changeset_action() doesn't hold any locks. The property could be changed before the changeset is applied. Signed-off-by: Rob Herring Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven --- drivers/of/dynamic.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 17a0727d3f9b..1876af5b01fc 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -564,7 +564,7 @@ static int __of_changeset_entry_notify(struct of_change= set_entry *ce, =20 static int __of_changeset_entry_apply(struct of_changeset_entry *ce) { - struct property *old_prop, **propp; + struct property **propp; unsigned long flags; int ret =3D 0; =20 @@ -604,7 +604,7 @@ static int __of_changeset_entry_apply(struct of_changes= et_entry *ce) } } =20 - ret =3D __of_update_property(ce->np, ce->prop, &old_prop); + ret =3D __of_update_property(ce->np, ce->prop, &ce->old_prop); break; default: ret =3D -EINVAL; @@ -908,9 +908,6 @@ int of_changeset_action(struct of_changeset *ocs, unsig= ned long action, ce->np =3D of_node_get(np); ce->prop =3D prop; =20 - if (action =3D=3D OF_RECONFIG_UPDATE_PROPERTY && prop) - ce->old_prop =3D of_find_property(np, prop->name, NULL); - /* add it to the list */ list_add_tail(&ce->node, &ocs->entries); return 0; --=20 2.40.1