diff options
| author | Prasad J Pandit <pjp@fedoraproject.org> | 2016-05-19 16:09:31 +0530 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2016-08-04 16:42:05 -0500 |
| commit | 9b28a7fc883f570f7aef582721deb16fd743bee4 (patch) | |
| tree | 5765ccb4195778ba91f82d28c88c7a433fa07a01 /hw | |
| parent | 0a5e3685ea10c578f8063ca0dbb009af45693d85 (diff) | |
esp: check dma length before reading scsi command(CVE-2016-4441)
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 <liqiang6-s@360.cn>
Cc: qemu-stable@nongnu.org
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <1463654371-11169-3-git-send-email-ppandit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 6c1fef6b59563cc415f21e03f81539ed4b33ad90)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/scsi/esp.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 01497e6740..591c8172d5 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; |