From patchwork Mon Sep 15 16:40:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andreas_F=C3=A4rber?= X-Patchwork-Id: 389429 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 18BA3140095 for ; Tue, 16 Sep 2014 02:42:11 +1000 (EST) Received: from localhost ([::1]:32937 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTZLt-0006J3-1S for incoming@patchwork.ozlabs.org; Mon, 15 Sep 2014 12:42:09 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50284) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTZK7-0003ta-Hd for qemu-devel@nongnu.org; Mon, 15 Sep 2014 12:40:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XTZK1-0006uX-CX for qemu-devel@nongnu.org; Mon, 15 Sep 2014 12:40:19 -0400 Received: from cantor2.suse.de ([195.135.220.15]:52379 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTZK1-0006uH-1f; Mon, 15 Sep 2014 12:40:13 -0400 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 45E5575031; Mon, 15 Sep 2014 16:40:12 +0000 (UTC) From: =?UTF-8?q?Andreas=20F=C3=A4rber?= To: qemu-devel@nongnu.org Date: Mon, 15 Sep 2014 18:40:05 +0200 Message-Id: <1410799208-3250-2-git-send-email-afaerber@suse.de> X-Mailer: git-send-email 1.8.4.5 In-Reply-To: <1410799208-3250-1-git-send-email-afaerber@suse.de> References: <1410799208-3250-1-git-send-email-afaerber@suse.de> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 195.135.220.15 Cc: Sebastian Krahmer , "Michael S. Tsirkin" , qemu-stable@nongnu.org, David Marchand , Bruce Rogers , Stefan Hajnoczi , Cam Macdonell , =?UTF-8?q?Andreas=20F=C3=A4rber?= Subject: [Qemu-devel] [PATCH v3 1/4] ivshmem: Check ivshmem_read() size argument X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Stefan Hajnoczi The third argument to the fd_read() callback implemented by ivshmem_read() is the number of bytes, not a flags field. Fix this and check we received enough bytes before accessing the buffer pointer. Cc: Cam Macdonell Reported-by: Sebastian Krahmer Signed-off-by: Stefan Hajnoczi [AF: Handle partial reads via FIFO] Reported-by: Peter Maydell Cc: qemu-stable@nongnu.org Signed-off-by: Andreas Färber Reviewed-by: Michael S. Tsirkin --- hw/misc/ivshmem.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index bd9d718..caeee1e 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -24,6 +24,7 @@ #include "migration/migration.h" #include "qapi/qmp/qerror.h" #include "qemu/event_notifier.h" +#include "qemu/fifo8.h" #include "sysemu/char.h" #include @@ -73,6 +74,7 @@ typedef struct IVShmemState { CharDriverState **eventfd_chr; CharDriverState *server_chr; + Fifo8 incoming_fifo; MemoryRegion ivshmem_mmio; /* We might need to register the BAR before we actually have the memory. @@ -424,14 +426,35 @@ static void increase_dynamic_storage(IVShmemState *s, int new_min_size) { } } -static void ivshmem_read(void *opaque, const uint8_t * buf, int flags) +static void ivshmem_read(void *opaque, const uint8_t *buf, int size) { IVShmemState *s = opaque; int incoming_fd, tmp_fd; int guest_max_eventfd; long incoming_posn; - memcpy(&incoming_posn, buf, sizeof(long)); + if (fifo8_is_empty(&s->incoming_fifo) && size == sizeof(incoming_posn)) { + memcpy(&incoming_posn, buf, size); + } else { + const uint8_t *p; + uint32_t num; + + IVSHMEM_DPRINTF("short read of %d bytes\n", size); + num = MAX(size, sizeof(long) - fifo8_num_used(&s->incoming_fifo)); + fifo8_push_all(&s->incoming_fifo, buf, num); + if (fifo8_num_used(&s->incoming_fifo) < sizeof(incoming_posn)) { + return; + } + size -= num; + buf += num; + p = fifo8_pop_buf(&s->incoming_fifo, sizeof(incoming_posn), &num); + g_assert(num == sizeof(incoming_posn)); + memcpy(&incoming_posn, p, sizeof(incoming_posn)); + if (size > 0) { + fifo8_push_all(&s->incoming_fifo, buf, size); + } + } + /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr); IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd); @@ -663,6 +686,8 @@ static int pci_ivshmem_init(PCIDevice *dev) s->ivshmem_size = ivshmem_get_size(s); } + fifo8_create(&s->incoming_fifo, sizeof(long)); + register_savevm(DEVICE(dev), "ivshmem", 0, 0, ivshmem_save, ivshmem_load, dev); @@ -796,6 +821,7 @@ static void pci_ivshmem_uninit(PCIDevice *dev) memory_region_del_subregion(&s->bar, &s->ivshmem); vmstate_unregister_ram(&s->ivshmem, DEVICE(dev)); unregister_savevm(DEVICE(dev), "ivshmem", s); + fifo8_destroy(&s->incoming_fifo); } static Property ivshmem_properties[] = {