qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH 052/156] zaurus: fix buffer overrun on invalid state


From: Michael Roth
Subject: [Qemu-devel] [PATCH 052/156] zaurus: fix buffer overrun on invalid state load
Date: Tue, 8 Jul 2014 12:17:23 -0500

From: "Michael S. Tsirkin" <address@hidden>

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 <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
(cherry picked from commit 52f91c3723932f8340fe36c8ec8b18a757c37b2b)
Signed-off-by: Michael Roth <address@hidden>
---
 hw/gpio/zaurus.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/gpio/zaurus.c b/hw/gpio/zaurus.c
index dc79a8b..8e2ce04 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),
-- 
1.9.1




reply via email to

[Prev in Thread] Current Thread [Next in Thread]