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authorMichael S. Tsirkin <mst@redhat.com>2014-04-03 19:52:13 +0300
committerJuan Quintela <quintela@redhat.com>2014-05-05 22:15:02 +0200
commit52f91c3723932f8340fe36c8ec8b18a757c37b2b (patch)
treef331a24f6d414648c3994cc0a25e3bc6ae3059e4 /hw/gpio/zaurus.c
parent5193be3be35f29a35bc465036cd64ad60d43385f (diff)
downloadfocaccia-qemu-52f91c3723932f8340fe36c8ec8b18a757c37b2b.tar.gz
focaccia-qemu-52f91c3723932f8340fe36c8ec8b18a757c37b2b.zip
zaurus: fix buffer overrun on invalid state load
CVE-2013-4540

Within scoop_gpio_handler_update, if prev_level has a high bit set, then
we get bit > 16 and that causes a buffer overrun.

Since prev_level comes from wire indirectly, this can
happen on invalid state load.

Similarly for gpio_level and gpio_dir.

To fix, limit to 16 bit.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Diffstat (limited to 'hw/gpio/zaurus.c')
-rw-r--r--hw/gpio/zaurus.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/hw/gpio/zaurus.c b/hw/gpio/zaurus.c
index dc79a8baa6..8e2ce049de 100644
--- a/hw/gpio/zaurus.c
+++ b/hw/gpio/zaurus.c
@@ -203,6 +203,15 @@ static bool is_version_0 (void *opaque, int version_id)
     return version_id == 0;
 }
 
+static bool vmstate_scoop_validate(void *opaque, int version_id)
+{
+    ScoopInfo *s = opaque;
+
+    return !(s->prev_level & 0xffff0000) &&
+        !(s->gpio_level & 0xffff0000) &&
+        !(s->gpio_dir & 0xffff0000);
+}
+
 static const VMStateDescription vmstate_scoop_regs = {
     .name = "scoop",
     .version_id = 1,
@@ -215,6 +224,7 @@ static const VMStateDescription vmstate_scoop_regs = {
         VMSTATE_UINT32(gpio_level, ScoopInfo),
         VMSTATE_UINT32(gpio_dir, ScoopInfo),
         VMSTATE_UINT32(prev_level, ScoopInfo),
+        VMSTATE_VALIDATE("irq levels are 16 bit", vmstate_scoop_validate),
         VMSTATE_UINT16(mcr, ScoopInfo),
         VMSTATE_UINT16(cdr, ScoopInfo),
         VMSTATE_UINT16(ccr, ScoopInfo),