From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA5DBC4363D for ; Tue, 6 Oct 2020 13:04:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36C5C20760 for ; Tue, 6 Oct 2020 13:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbgJFNEm (ORCPT ); Tue, 6 Oct 2020 09:04:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50852 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgJFNEl (ORCPT ); Tue, 6 Oct 2020 09:04:41 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 379AEC061755; Tue, 6 Oct 2020 06:04:41 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id BF84C127C5E92; Tue, 6 Oct 2020 05:47:50 -0700 (PDT) Date: Tue, 06 Oct 2020 06:02:47 -0700 (PDT) Message-Id: <20201006.060247.672466449778345455.davem@davemloft.net> To: manivannan.sadhasivam@linaro.org Cc: kuba@kernel.org, bjorn.andersson@linaro.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dianders@chromium.org, elder@linaro.org Subject: Re: [PATCH v3] net: qrtr: ns: Fix the incorrect usage of rcu_read_lock() From: David Miller In-Reply-To: <20201005071642.9621-1-manivannan.sadhasivam@linaro.org> References: <20201005071642.9621-1-manivannan.sadhasivam@linaro.org> X-Mailer: Mew version 6.8 on Emacs 27.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [2620:137:e000::1:9]); Tue, 06 Oct 2020 05:47:51 -0700 (PDT) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Manivannan Sadhasivam Date: Mon, 5 Oct 2020 12:46:42 +0530 > The rcu_read_lock() is not supposed to lock the kernel_sendmsg() API > since it has the lock_sock() in qrtr_sendmsg() which will sleep. Hence, > fix it by excluding the locking for kernel_sendmsg(). > > While at it, let's also use radix_tree_deref_retry() to confirm the > validity of the pointer returned by radix_tree_deref_slot() and use > radix_tree_iter_resume() to resume iterating the tree properly before > releasing the lock as suggested by Doug. > > Fixes: a7809ff90ce6 ("net: qrtr: ns: Protect radix_tree_deref_slot() using rcu read locks") > Reported-by: Douglas Anderson > Reviewed-by: Douglas Anderson > Tested-by: Douglas Anderson > Tested-by: Alex Elder > Signed-off-by: Manivannan Sadhasivam Applied, thank you.