From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37669) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4rUu-0002Im-Ms for qemu-devel@nongnu.org; Mon, 23 May 2016 11:10:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b4rUr-000485-Ct for qemu-devel@nongnu.org; Mon, 23 May 2016 11:10:24 -0400 Sender: Paolo Bonzini From: Paolo Bonzini Date: Mon, 23 May 2016 17:09:53 +0200 Message-Id: <1464016199-43768-19-git-send-email-pbonzini@redhat.com> In-Reply-To: <1464016199-43768-1-git-send-email-pbonzini@redhat.com> References: <1464016199-43768-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PULL 18/24] esp: check command buffer length before write(CVE-2016-4439) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Prasad J Pandit , qemu-stable@nongnu.org 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 Cc: qemu-stable@nongnu.org Signed-off-by: Prasad J Pandit Message-Id: <1463654371-11169-2-git-send-email-ppandit@redhat.com> Signed-off-by: Paolo Bonzini --- 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 { -- 1.8.3.1