From: Prasad J Pandit <pjp@fedoraproject.org>

Date: Tue, 31 May 2016 23:23:27 +0530

Subject: [PATCH] scsi: esp: check buffer length before reading scsi command

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() in non-DMA mode, uses 'ti_size' to read scsi

command into a buffer. Add check to validate command length against

buffer size to avoid any overrun.

Reported-by: Li Qiang <liqiang6-s@360.cn>

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>

Message-Id: <1464717207-7549-1-git-send-email-ppandit@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit d3cdc49138c30be1d3c2f83d18f85d9fdee95f1a)

---

 hw/scsi/esp.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c

index 591c817..c2f6f8f 100644

--- a/hw/scsi/esp.c

+++ b/hw/scsi/esp.c

@@ -98,6 +98,9 @@ static uint32_t get_cmd(ESPState *s, uint8_t *buf, uint8_t buflen)

         s->dma_memory_read(s->dma_opaque, buf, dmalen);

     } else {

         dmalen = s->ti_size;

+        if (dmalen > TI_BUFSZ) {

+            return 0;

+        }

         memcpy(buf, s->ti_buf, dmalen);

         buf[0] = buf[2] >> 5;

     }