diff mbox series

[PULL,11/17] lsi53c895a: check message length value is valid

Message ID 1541540283-45699-12-git-send-email-pbonzini@redhat.com
State New
Headers show
Series [PULL,01/17] icount: fix deadlock when all cpus are sleeping | expand

Commit Message

Paolo Bonzini Nov. 6, 2018, 9:37 p.m. UTC 
From: Prasad J Pandit <pjp@fedoraproject.org>

While writing a message in 'lsi_do_msgin', message length value
in 'msg_len' could be invalid due to an invalid migration stream.
Add an assertion to avoid an out of bounds access, and reject
the incoming migration data if it contains an invalid message
length.

Discovered by Deja vu Security. Reported by Oracle.

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <20181026194314.18663-1-ppandit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/scsi/lsi53c895a.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c
index d1e6534..3f207f6 100644
--- a/hw/scsi/lsi53c895a.c
+++ b/hw/scsi/lsi53c895a.c
@@ -861,10 +861,11 @@  static void lsi_do_status(LSIState *s)
 
 static void lsi_do_msgin(LSIState *s)
 {
-    int len;
+    uint8_t len;
     trace_lsi_do_msgin(s->dbc, s->msg_len);
     s->sfbr = s->msg[0];
     len = s->msg_len;
+    assert(len > 0 && len <= LSI_MAX_MSGIN_LEN);
     if (len > s->dbc)
         len = s->dbc;
     pci_dma_write(PCI_DEVICE(s), s->dnad, s->msg, len);
@@ -1705,8 +1706,10 @@  static uint8_t lsi_reg_readb(LSIState *s, int offset)
         break;
     case 0x58: /* SBDL */
         /* Some drivers peek at the data bus during the MSG IN phase.  */
-        if ((s->sstat1 & PHASE_MASK) == PHASE_MI)
+        if ((s->sstat1 & PHASE_MASK) == PHASE_MI) {
+            assert(s->msg_len > 0);
             return s->msg[0];
+        }
         ret = 0;
         break;
     case 0x59: /* SBDL high */
@@ -2103,11 +2106,23 @@  static int lsi_pre_save(void *opaque)
     return 0;
 }
 
+static int lsi_post_load(void *opaque, int version_id)
+{
+    LSIState *s = opaque;
+
+    if (s->msg_len < 0 || s->msg_len > LSI_MAX_MSGIN_LEN) {
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
 static const VMStateDescription vmstate_lsi_scsi = {
     .name = "lsiscsi",
     .version_id = 0,
     .minimum_version_id = 0,
     .pre_save = lsi_pre_save,
+    .post_load = lsi_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, LSIState),