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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 7D65DC4727C for ; Tue, 29 Sep 2020 12:23:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A2882076B for ; Tue, 29 Sep 2020 12:23:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601382182; bh=J+DVPE/WCTi2SxBKzJYHwhm+7eW5FHl8NKJjIx3duh4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fa2NwXhLlylueyZXumLmmfsGwfJH0sHOTsXxe/LvFXhCBX1siu6/MNKIgnXc8Q3Tg TYGKfUPWwpkgrOW7NBb/ZGzcfrCY632a6qmQ2n1cjpusp7MdqfGX/qW612uiIbU4sZ SFCZ3xTcJ53Iy+mRomm0BGYE3I5OjzHYwiRISGN8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732593AbgI2MXA (ORCPT ); Tue, 29 Sep 2020 08:23:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:49816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729786AbgI2LfK (ORCPT ); Tue, 29 Sep 2020 07:35:10 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A56EB23CD5; Tue, 29 Sep 2020 11:29:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601378951; bh=J+DVPE/WCTi2SxBKzJYHwhm+7eW5FHl8NKJjIx3duh4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hLV08ZHOoIo39ZTjQpQy3gdkTaiGpyoxFXHzRbDW5uzn2ar6QpPHh5L2zOzPayitx FTbKt75F/5OCh8Y9pOmpHVwhEiP5JbRNVw9klmpEs1ChvTR0QlsNv4naJkZZSst7yn C8yoPP4GErIBPWj6T2EHzamZIQlIxbI1rDrEy5KY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Girish Basrur , Saurav Kashyap , Shyam Sundar , Javed Hasan , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.19 198/245] scsi: libfc: Skip additional kref updating work event Date: Tue, 29 Sep 2020 13:00:49 +0200 Message-Id: <20200929105956.608881155@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105946.978650816@linuxfoundation.org> References: <20200929105946.978650816@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Javed Hasan [ Upstream commit 823a65409c8990f64c5693af98ce0e7819975cba ] When an rport event (RPORT_EV_READY) is updated without work being queued, avoid taking an additional reference. This issue was leading to memory leak. Trace from KMEMLEAK tool: unreferenced object 0xffff8888259e8780 (size 512): comm "kworker/2:1", jiffies 4433237386 (age 113021.971s) hex dump (first 32 bytes): 58 0a ec cf 83 88 ff ff 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 13 7d f0 1e 0e 00 00 10 backtrace: [<000000006b25760f>] fc_rport_recv_req+0x3c6/0x18f0 [libfc] [<00000000f208d994>] fc_lport_recv_els_req+0x120/0x8a0 [libfc] [<00000000a9c437b8>] fc_lport_recv+0xb9/0x130 [libfc] [<00000000a9c437b8>] fc_lport_recv+0xb9/0x130 [libfc] [<00000000ad5be37b>] qedf_ll2_process_skb+0x73d/0xad0 [qedf] [<00000000e0eb6893>] process_one_work+0x382/0x6c0 [<000000002dfd9e21>] worker_thread+0x57/0x5c0 [<00000000b648204f>] kthread+0x1a0/0x1c0 [<0000000072f5ab20>] ret_from_fork+0x35/0x40 [<000000001d5c05d8>] 0xffffffffffffffff Below is the log sequence which leads to memory leak. Here we get the RPORT_EV_READY and RPORT_EV_STOP back to back, which lead to overwrite the event RPORT_EV_READY by event RPORT_EV_STOP. Because of this, kref_count gets incremented by 1. kernel: host0: rport fffce5: Received PLOGI request kernel: host0: rport fffce5: Received PLOGI in INIT state kernel: host0: rport fffce5: Port is Ready kernel: host0: rport fffce5: Received PRLI request while in state Ready kernel: host0: rport fffce5: PRLI rspp type 8 active 1 passive 0 kernel: host0: rport fffce5: Received LOGO request while in state Ready kernel: host0: rport fffce5: Delete port kernel: host0: rport fffce5: Received PLOGI request kernel: host0: rport fffce5: Received PLOGI in state Delete - send busy kernel: host0: rport fffce5: work event 3 kernel: host0: rport fffce5: lld callback ev 3 kernel: host0: rport fffce5: work delete Link: https://lore.kernel.org/r/20200626094959.32151-1-jhasan@marvell.com Reviewed-by: Girish Basrur Reviewed-by: Saurav Kashyap Reviewed-by: Shyam Sundar Signed-off-by: Javed Hasan Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/libfc/fc_rport.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c index f39d2d62b002f..2b3239765c249 100644 --- a/drivers/scsi/libfc/fc_rport.c +++ b/drivers/scsi/libfc/fc_rport.c @@ -495,10 +495,11 @@ static void fc_rport_enter_delete(struct fc_rport_priv *rdata, fc_rport_state_enter(rdata, RPORT_ST_DELETE); - kref_get(&rdata->kref); - if (rdata->event == RPORT_EV_NONE && - !queue_work(rport_event_queue, &rdata->event_work)) - kref_put(&rdata->kref, fc_rport_destroy); + if (rdata->event == RPORT_EV_NONE) { + kref_get(&rdata->kref); + if (!queue_work(rport_event_queue, &rdata->event_work)) + kref_put(&rdata->kref, fc_rport_destroy); + } rdata->event = event; } -- 2.25.1