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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 76ED4C4338F for ; Mon, 26 Jul 2021 16:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6142D60F11 for ; Mon, 26 Jul 2021 16:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232911AbhGZPxw (ORCPT ); Mon, 26 Jul 2021 11:53:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:48228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232959AbhGZPcL (ORCPT ); Mon, 26 Jul 2021 11:32:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5969A60F5E; Mon, 26 Jul 2021 16:12:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627315925; bh=fP855E9686zR6CXMsZpON5/Cf6HNpGS9rJ5YroC0iiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wjSCMqaJ7I8zmcGjwtFNo0XeOt+Msh0ASc7xwRUtPZb2JTaHCxTqAy6r9e++uCedl ZI9A/p8DWjHcnMyt05hj54euM6tupfNVZCR9Vs6rr13nf4nZ2941fAc9+i+Me6A5Qz KNgGqKAqUbLoH2AgCSzntQd6T1/Ql5zEJla7vYrQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lee Duncan , Mike Christie , David Disseldorp , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.13 121/223] scsi: target: Fix NULL dereference on XCOPY completion Date: Mon, 26 Jul 2021 17:38:33 +0200 Message-Id: <20210726153850.228528804@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153846.245305071@linuxfoundation.org> References: <20210726153846.245305071@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: David Disseldorp [ Upstream commit a47fa41381a09e5997afd762664db4f5f6657e03 ] CPU affinity control added with commit 39ae3edda325 ("scsi: target: core: Make completion affinity configurable") makes target_complete_cmd() queue work on a CPU based on se_tpg->se_tpg_wwn->cmd_compl_affinity state. LIO's EXTENDED COPY worker is a special case in that read/write cmds are dispatched using the global xcopy_pt_tpg, which carries a NULL se_tpg_wwn pointer following initialization in target_xcopy_setup_pt(). The NULL xcopy_pt_tpg->se_tpg_wwn pointer is dereferenced on completion of any EXTENDED COPY initiated read/write cmds. E.g using the libiscsi SCSI.ExtendedCopy.Simple test: BUG: kernel NULL pointer dereference, address: 00000000000001a8 RIP: 0010:target_complete_cmd+0x9d/0x130 [target_core_mod] Call Trace: fd_execute_rw+0x148/0x42a [target_core_file] ? __dynamic_pr_debug+0xa7/0xe0 ? target_check_reservation+0x5b/0x940 [target_core_mod] __target_execute_cmd+0x1e/0x90 [target_core_mod] transport_generic_new_cmd+0x17c/0x330 [target_core_mod] target_xcopy_issue_pt_cmd+0x9/0x60 [target_core_mod] target_xcopy_read_source.isra.7+0x10b/0x1b0 [target_core_mod] ? target_check_fua+0x40/0x40 [target_core_mod] ? transport_complete_task_attr+0x130/0x130 [target_core_mod] target_xcopy_do_work+0x61f/0xc00 [target_core_mod] This fix makes target_complete_cmd() queue work on se_cmd->cpuid if se_tpg_wwn is NULL. Link: https://lore.kernel.org/r/20210720225522.26291-1-ddiss@suse.de Fixes: 39ae3edda325 ("scsi: target: core: Make completion affinity configurable") Cc: Lee Duncan Cc: Mike Christie Reviewed-by: Mike Christie Signed-off-by: David Disseldorp Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/target_core_transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 7e35eddd9eb7..26ceabe34de5 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -886,7 +886,7 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status) INIT_WORK(&cmd->work, success ? target_complete_ok_work : target_complete_failure_work); - if (wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID) + if (!wwn || wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID) cpu = cmd->cpuid; else cpu = wwn->cmd_compl_affinity; -- 2.30.2