[Qemu-devel] [PATCH 18/23] ssd0323: fix buffer overun on invalid state load

[Michael S. Tsirkin]

CVE-2013-4538

s->cmd_len used as index in ssd0323_transfer() to store 32-bit field.
Possible this field might then be supplied by guest to overwrite a
return addr somewhere. Same for row/col fields, which are indicies into
framebuffer array.

To fix validate after load.

Signed-off-by: Michael S. Tsirkin <address@hidden>
---
 hw/display/ssd0323.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/display/ssd0323.c b/hw/display/ssd0323.c
index c3231c6..2c82598 100644
--- a/hw/display/ssd0323.c
+++ b/hw/display/ssd0323.c
@@ -312,6 +312,9 @@ static int ssd0323_load(QEMUFile *f, void *opaque, int 
version_id)
         return -EINVAL;
 
     s->cmd_len = qemu_get_be32(f);
+    if (s->cmd_len < 0 || s->cmd_len > ARRAY_SIZE(s->cmd_data)) {
+        return -EINVAL;
+    }
     s->cmd = qemu_get_be32(f);
     for (i = 0; i < 8; i++)
         s->cmd_data[i] = qemu_get_be32(f);
-- 
MST