From patchwork Tue Mar 7 16:57:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 13164546 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 9E924C6FD20 for ; Tue, 7 Mar 2023 18:36:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230301AbjCGSgl (ORCPT ); Tue, 7 Mar 2023 13:36:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233094AbjCGSfI (ORCPT ); Tue, 7 Mar 2023 13:35:08 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2CE6B1B12; Tue, 7 Mar 2023 10:27:15 -0800 (PST) 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 1FDCEB819D8; Tue, 7 Mar 2023 18:26:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A46CC433EF; Tue, 7 Mar 2023 18:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678213617; bh=ei3myPUYHO43ooPPsEK8Ufm4tloujqlPCCmu7qPEaaQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D/NRjnzVVbzdGGWr9PCR/+VhJ+0WEicBLmMaNE6EtE+d2j8v+z2dmkc1LzIcDxuaW cQpYVpf3UcGhwpKBmL+hZMXKyc1JBxvL6X3TxNFpt/dpu7LypncASRhqRpihKKVwrV ux61+e6ypXBqhyBk2ZSBa/fzJvSo5J0VhPdAeYkw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe , Steven Rostedt , Masami Hiramatsu , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Bart Van Assche , Sasha Levin Subject: [PATCH 6.1 537/885] trace/blktrace: fix memory leak with using debugfs_lookup() Date: Tue, 7 Mar 2023 17:57:51 +0100 Message-Id: <20230307170025.828526424@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170001.594919529@linuxfoundation.org> References: <20230307170001.594919529@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org From: Greg Kroah-Hartman [ Upstream commit 83e8864fee26f63a7435e941b7c36a20fd6fe93e ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: Jens Axboe Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Reviewed-by: Bart Van Assche Link: https://lore.kernel.org/r/20230202141956.2299521-1-gregkh@linuxfoundation.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- kernel/trace/blktrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index a66cff5a18579..a5b35bcfb0602 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -320,8 +320,8 @@ static void blk_trace_free(struct request_queue *q, struct blk_trace *bt) * under 'q->debugfs_dir', thus lookup and remove them. */ if (!bt->dir) { - debugfs_remove(debugfs_lookup("dropped", q->debugfs_dir)); - debugfs_remove(debugfs_lookup("msg", q->debugfs_dir)); + debugfs_lookup_and_remove("dropped", q->debugfs_dir); + debugfs_lookup_and_remove("msg", q->debugfs_dir); } else { debugfs_remove(bt->dir); }