From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43296) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmOUq-0007NN-29 for qemu-devel@nongnu.org; Tue, 20 Sep 2016 13:06:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bmOUm-0007RS-7P for qemu-devel@nongnu.org; Tue, 20 Sep 2016 13:06:14 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50119) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmOUl-0007Pp-Tf for qemu-devel@nongnu.org; Tue, 20 Sep 2016 13:06:12 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u8KH3YiM054795 for ; Tue, 20 Sep 2016 13:06:11 -0400 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0a-001b2d01.pphosted.com with ESMTP id 25k7bhwpuv-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 20 Sep 2016 13:06:11 -0400 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 20 Sep 2016 11:06:09 -0600 From: Michael Roth Date: Tue, 20 Sep 2016 12:05:32 -0500 In-Reply-To: <1474391141-16623-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1474391141-16623-1-git-send-email-mdroth@linux.vnet.ibm.com> Message-Id: <1474391141-16623-17-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 16/25] scsi: pvscsi: limit process IO loop to ring size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Prasad J Pandit , Paolo Bonzini From: Prasad J Pandit Vmware Paravirtual SCSI emulator while processing IO requests could run into an infinite loop if 'pvscsi_ring_pop_req_descr' always returned positive value. Limit IO loop to the ring size. Cc: qemu-stable@nongnu.org Reported-by: Li Qiang Signed-off-by: Prasad J Pandit Message-Id: <1473845952-30785-1-git-send-email-ppandit@redhat.com> Signed-off-by: Paolo Bonzini (cherry picked from commit d251157ac1928191af851d199a9ff255d330bec9) Signed-off-by: Michael Roth --- hw/scsi/vmw_pvscsi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index 2d7528d..fe74d86 100644 --- a/hw/scsi/vmw_pvscsi.c +++ b/hw/scsi/vmw_pvscsi.c @@ -252,8 +252,11 @@ static hwaddr pvscsi_ring_pop_req_descr(PVSCSIRingInfo *mgr) { uint32_t ready_ptr = RS_GET_FIELD(mgr, reqProdIdx); + uint32_t ring_size = PVSCSI_MAX_NUM_PAGES_REQ_RING + * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE; - if (ready_ptr != mgr->consumed_ptr) { + if (ready_ptr != mgr->consumed_ptr + && ready_ptr - mgr->consumed_ptr < ring_size) { uint32_t next_ready_ptr = mgr->consumed_ptr++ & mgr->txr_len_mask; uint32_t next_ready_page = -- 1.9.1