From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45066 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968750AbeCSSQR (ORCPT ); Mon, 19 Mar 2018 14:16:17 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , Hannes Reinecke , Johannes Thumshirn , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.4 074/134] scsi: sg: close race condition in sg_remove_sfp_usercontext() Date: Mon, 19 Mar 2018 19:05:57 +0100 Message-Id: <20180319171859.944040060@linuxfoundation.org> In-Reply-To: <20180319171849.024066323@linuxfoundation.org> References: <20180319171849.024066323@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hannes Reinecke [ Upstream commit 97d27b0dd015e980ade63fda111fd1353276e28b ] 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 --- drivers/scsi/sg.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -535,6 +535,7 @@ 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); @@ -575,6 +576,7 @@ 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; } @@ -811,6 +813,7 @@ sg_common_write(Sg_fd * sfp, Sg_request SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp, "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)) { @@ -823,6 +826,7 @@ sg_common_write(Sg_fd * sfp, Sg_request } sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return -ENODEV; } @@ -1312,6 +1316,7 @@ 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); } @@ -1856,8 +1861,6 @@ sg_finish_rem_req(Sg_request *srp) else sg_remove_scat(sfp, req_schp); - sg_remove_request(sfp, srp); - return ret; } @@ -2204,12 +2207,17 @@ 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, sg_printk(KERN_INFO, sdp,