From patchwork Tue Mar 7 16:56:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 13164298 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 DDD88C678D4 for ; Tue, 7 Mar 2023 17:44:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232103AbjCGRoc (ORCPT ); Tue, 7 Mar 2023 12:44:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231825AbjCGRoQ (ORCPT ); Tue, 7 Mar 2023 12:44:16 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21E5995E2D; Tue, 7 Mar 2023 09:40:03 -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 dfw.source.kernel.org (Postfix) with ESMTPS id EDFDC6150F; Tue, 7 Mar 2023 17:40:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 089ACC4339B; Tue, 7 Mar 2023 17:40:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678210802; bh=LeQHH3A/YVVZ58VA0ghtE+gGqnsXTxc4CFRT2Hs5Ukw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2gcyqtS6qNaq4Ip3pLV2Ye3RiQF8tU1VewsXO8Fmb8o3xzeYFn7Me2+IceGyfCNeE IFilnnxYxR2TZ5ZID6ficdj6JY74o0YGuziXn4PzRVcJPJr7LuCG4UpCV+S74VHGQq v/hue8EpI2Yr7mFo9JsmjXvYBPeUOOFT5KCXseB8= 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 6.2 0628/1001] trace/blktrace: fix memory leak with using debugfs_lookup() Date: Tue, 7 Mar 2023 17:56:40 +0100 Message-Id: <20230307170048.806712929@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@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 918a7d12df8ff..5743be5594153 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); }