From 985b046012f258fd5a2164fb85e9d792f574697c Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 3 Apr 2014 19:52:13 +0300 Subject: [PATCH] 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 Signed-off-by: Michael S. Tsirkin Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Juan Quintela (cherry picked from commit 52f91c3723932f8340fe36c8ec8b18a757c37b2b) --- 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),