From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41503) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWrjw-0003mN-Bt for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bWrjs-0005qA-Oa for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:40 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43024 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWrjs-0005ps-Cu for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:36 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u78KxkQh024507 for ; Mon, 8 Aug 2016 17:05:36 -0400 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx0b-001b2d01.pphosted.com with ESMTP id 24n9h0bvw2-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 08 Aug 2016 17:05:35 -0400 Received: from localhost by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 8 Aug 2016 15:05:34 -0600 From: Michael Roth Date: Mon, 8 Aug 2016 16:03:45 -0500 In-Reply-To: <1470690267-31454-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1470690267-31454-1-git-send-email-mdroth@linux.vnet.ibm.com> Message-Id: <1470690267-31454-15-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 14/56] esp: check dma length before reading scsi command(CVE-2016-4441) 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 The 53C9X Fast SCSI Controller(FSC) comes with an internal 16-byte FIFO buffer. It is used to handle command and data transfer. Routine get_cmd() uses DMA to read scsi commands into this buffer. Add check to validate DMA length against buffer size to avoid any overrun. Fixes CVE-2016-4441. Reported-by: Li Qiang Cc: qemu-stable@nongnu.org Signed-off-by: Prasad J Pandit Message-Id: <1463654371-11169-3-git-send-email-ppandit@redhat.com> Signed-off-by: Paolo Bonzini (cherry picked from commit 6c1fef6b59563cc415f21e03f81539ed4b33ad90) Signed-off-by: Michael Roth --- hw/scsi/esp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 01497e6..591c817 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -82,7 +82,7 @@ void esp_request_cancelled(SCSIRequest *req) } } -static uint32_t get_cmd(ESPState *s, uint8_t *buf) +static uint32_t get_cmd(ESPState *s, uint8_t *buf, uint8_t buflen) { uint32_t dmalen; int target; @@ -92,6 +92,9 @@ static uint32_t get_cmd(ESPState *s, uint8_t *buf) dmalen = s->rregs[ESP_TCLO]; dmalen |= s->rregs[ESP_TCMID] << 8; dmalen |= s->rregs[ESP_TCHI] << 16; + if (dmalen > buflen) { + return 0; + } s->dma_memory_read(s->dma_opaque, buf, dmalen); } else { dmalen = s->ti_size; @@ -166,7 +169,7 @@ static void handle_satn(ESPState *s) s->dma_cb = handle_satn; return; } - len = get_cmd(s, buf); + len = get_cmd(s, buf, sizeof(buf)); if (len) do_cmd(s, buf); } @@ -180,7 +183,7 @@ static void handle_s_without_atn(ESPState *s) s->dma_cb = handle_s_without_atn; return; } - len = get_cmd(s, buf); + len = get_cmd(s, buf, sizeof(buf)); if (len) { do_busid_cmd(s, buf, 0); } @@ -192,7 +195,7 @@ static void handle_satn_stop(ESPState *s) s->dma_cb = handle_satn_stop; return; } - s->cmdlen = get_cmd(s, s->cmdbuf); + s->cmdlen = get_cmd(s, s->cmdbuf, sizeof(s->cmdbuf)); if (s->cmdlen) { trace_esp_handle_satn_stop(s->cmdlen); s->do_cmd = 1; -- 1.9.1