Re: [RELEASE] Lguest for 2.6.21

[WANG Cong <xiyou.wangcong@gmail.com>]

On Thu, May 03, 2007 at 03:33:03AM +0800, WANG Cong wrote:
>Hi Rusty!
>
>I found you forgot to check the return value of copy_from_user, and here is the fix for drivers/lguest/interrupts_and_traps.c.
>

Also this one, in drivers/lguest/hypercalls.c.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>

---

--- linux-2.6.21-rc7-mm2/drivers/lguest/hypercalls.c.orig	2007-05-03 03:45:53.000000000 +0800
+++ linux-2.6.21-rc7-mm2/drivers/lguest/hypercalls.c	2007-05-03 03:46:20.000000000 +0800
@@ -102,7 +102,8 @@ static void do_async_hcalls(struct lgues
 	unsigned int i;
 	u8 st[LHCALL_RING_SIZE];
 
-	copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st));
+	if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
+		return;
 	for (i = 0; i < ARRAY_SIZE(st); i++) {
 		struct lguest_regs regs;
 		unsigned int n = lg->next_hcall;