From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54160) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b3LMw-00065I-Vw for qemu-devel@nongnu.org; Thu, 19 May 2016 06:39:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b3LMq-0001bQ-0C for qemu-devel@nongnu.org; Thu, 19 May 2016 06:39:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57637) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b3LMp-0001bC-Qe for qemu-devel@nongnu.org; Thu, 19 May 2016 06:39:47 -0400 From: P J P Date: Thu, 19 May 2016 16:09:30 +0530 Message-Id: <1463654371-11169-2-git-send-email-ppandit@redhat.com> In-Reply-To: <1463654371-11169-1-git-send-email-ppandit@redhat.com> References: <1463654371-11169-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH 1/2] scsi: check command buffer length before write(CVE-2016-4439) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Paolo Bonzini , Li Qiang , Prasad J Pandit 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. While writing to this command buffer 's->cmdbuf[TI_BUFSZ=16]', a check was missing to validate input length. Add check to avoid OOB write access. Fixes CVE-2016-4439 Reported-by: Li Qiang Signed-off-by: Prasad J Pandit --- hw/scsi/esp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 8961be2..01497e6 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -448,7 +448,11 @@ void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val) break; case ESP_FIFO: if (s->do_cmd) { - s->cmdbuf[s->cmdlen++] = val & 0xff; + if (s->cmdlen < TI_BUFSZ) { + s->cmdbuf[s->cmdlen++] = val & 0xff; + } else { + trace_esp_error_fifo_overrun(); + } } else if (s->ti_size == TI_BUFSZ - 1) { trace_esp_error_fifo_overrun(); } else { -- 2.5.5