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=-3.7 required=3.0 tests=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 397CAC433E0 for ; Tue, 9 Jun 2020 18:07:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D99620734 for ; Tue, 9 Jun 2020 18:07:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388339AbgFISHc (ORCPT ); Tue, 9 Jun 2020 14:07:32 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41510 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388194AbgFISF7 (ORCPT ); Tue, 9 Jun 2020 14:05:59 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jiidG-0001pb-Hv; Tue, 09 Jun 2020 19:05:54 +0100 Received: from ben by deadeye with local (Exim 4.94) (envelope-from ) id 1jiidF-006VwL-J4; Tue, 09 Jun 2020 19:05:53 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Christoph Hellwig" , "Johannes Thumshirn" , "Martin K. Petersen" , "Greg Kroah-Hartman" , "Sasha Levin" , "Hannes Reinecke" , "Hannes Reinecke" Date: Tue, 09 Jun 2020 19:04:29 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 38/61] scsi: sg: close race condition in sg_remove_sfp_usercontext() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.85-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Hannes Reinecke commit 97d27b0dd015e980ade63fda111fd1353276e28b upstream. sg_remove_sfp_usercontext() is clearing any sg requests, but needs to take 'rq_list_lock' when modifying the list. Reported-by: Christoph Hellwig Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Tested-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/scsi/sg.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -561,6 +561,7 @@ sg_read(struct file *filp, char __user * } else count = (old_hdr->result == 0) ? 0 : -EIO; sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); retval = count; free_old_hdr: kfree(old_hdr); @@ -601,6 +602,7 @@ sg_new_read(Sg_fd * sfp, char __user *bu } err_out: err2 = sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return err ? : err2 ? : count; } @@ -835,6 +837,7 @@ sg_common_write(Sg_fd * sfp, Sg_request if (k) { SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k)); sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return k; /* probably out of space --> ENOMEM */ } if (atomic_read(&sdp->detaching)) { @@ -844,6 +847,7 @@ sg_common_write(Sg_fd * sfp, Sg_request } sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return -ENODEV; } @@ -1367,6 +1371,7 @@ sg_rq_end_io_usercontext(struct work_str struct sg_fd *sfp = srp->parentfp; sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); kref_put(&sfp->f_ref, sg_remove_sfp); } @@ -1876,8 +1881,6 @@ sg_finish_rem_req(Sg_request *srp) else sg_remove_scat(req_schp); - sg_remove_request(sfp, srp); - return ret; } @@ -2211,12 +2214,17 @@ sg_remove_sfp_usercontext(struct work_st struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work); struct sg_device *sdp = sfp->parentdp; Sg_request *srp; + unsigned long iflags; /* Cleanup any responses which were never read(). */ + write_lock_irqsave(&sfp->rq_list_lock, iflags); while (!list_empty(&sfp->rq_list)) { srp = list_first_entry(&sfp->rq_list, Sg_request, entry); sg_finish_rem_req(srp); + list_del(&srp->entry); + srp->parentfp = NULL; } + write_unlock_irqrestore(&sfp->rq_list_lock, iflags); if (sfp->reserve.bufflen > 0) { SCSI_LOG_TIMEOUT(6,