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 2157A1A7076; Thu, 15 Aug 2024 14:17:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723731475; cv=none; b=lqYjNB65GRfvPOEW00ZVkg3wxce8Jhgtkw48O9R2plrZnLNgREXUuo4Y8eYgvhkNCgamUTLLrvoidNATaT7ORq4Tg5AG/M/Y4Yy16ji0OTM+HiB5ACPnaBmfrqWyBg+ybuvOpX92OpaeVK/6az1CGXaHoy+RafbOYFWZ6TUSuj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723731475; c=relaxed/simple; bh=GcO3ljyDLla9Sm9DT69AzwUFC8QGqe1BE+/g7BfRLrM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GiBZUt18IjDO/cUu4EM5ZzQXiGj03kgZkuvj57w6vBHNXvBNpON6eO5eOMm9ytlW4jbNVQ8kIyLEY72hil8XNnZLEZrapvQQA/Dv3NB/gDfsRKUFLQeACQ+fdvA7zRNL9w/AoQWn8o5urfGC03BEfvhJyMlp5RL/JCOCsAIOhHg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mMDnR24i; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mMDnR24i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A9E5C32786; Thu, 15 Aug 2024 14:17:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723731475; bh=GcO3ljyDLla9Sm9DT69AzwUFC8QGqe1BE+/g7BfRLrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mMDnR24ip4g0UROkYaelqXvEMDf1lUm+NmDPjOvCQZuuINyuzNgUsYBuGNQrMoiKv oeyJrmo4BpFZlEmbdVDVqZJ5VkBlqHxKecKz8/WIa3ohFcRrq8rhn0Ju4UoMb479dd /h9kqHCnv8xdI+0e9gtz3MjXLV3QEc0Fl1ysGQXQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiri Pirko , Johannes Berg , Jay Vosburgh , Paolo Abeni , Sasha Levin Subject: [PATCH 5.4 142/259] net: bonding: correctly annotate RCU in bond_should_notify_peers() Date: Thu, 15 Aug 2024 15:24:35 +0200 Message-ID: <20240815131908.274959303@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240815131902.779125794@linuxfoundation.org> References: <20240815131902.779125794@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 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg [ Upstream commit 3ba359c0cd6eb5ea772125a7aededb4a2d516684 ] RCU use in bond_should_notify_peers() looks wrong, since it does rcu_dereference(), leaves the critical section, and uses the pointer after that. Luckily, it's called either inside a nested RCU critical section or with the RTNL held. Annotate it with rcu_dereference_rtnl() instead, and remove the inner RCU critical section. Fixes: 4cb4f97b7e36 ("bonding: rebuild the lock use for bond_mii_monitor()") Reviewed-by: Jiri Pirko Signed-off-by: Johannes Berg Acked-by: Jay Vosburgh Link: https://patch.msgid.link/20240719094119.35c62455087d.I68eb9c0f02545b364b79a59f2110f2cf5682a8e2@changeid Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/bonding/bond_main.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index bb1c6743222e5..89797b2575733 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -784,13 +784,10 @@ static struct slave *bond_find_best_slave(struct bonding *bond) return bestslave; } +/* must be called in RCU critical section or with RTNL held */ static bool bond_should_notify_peers(struct bonding *bond) { - struct slave *slave; - - rcu_read_lock(); - slave = rcu_dereference(bond->curr_active_slave); - rcu_read_unlock(); + struct slave *slave = rcu_dereference_rtnl(bond->curr_active_slave); if (!slave || !bond->send_peer_notif || bond->send_peer_notif % -- 2.43.0