From 49c37c0334a9b85d30ab3d6b5d1acb05ef2ef6de Mon Sep 17 00:00:00 2001
From: Dan Rosenberg <drosenberg@vsecurity.com>
Date: Wed, 15 Sep 2010 11:43:12 +0000
Subject: [PATCH] drivers/net/cxgb3/cxgb3_main.c: prevent reading uninitialized
stack memory
Fixed formatting (tabs and line breaks).
The CHELSIO_GET_QSET_NUM device ioctl allows unprivileged users to read
4 bytes of uninitialized stack memory, because the "addr" member of the
ch_reg struct declared on the stack in cxgb_extension_ioctl() is not
altered or zeroed before being copied back to the user. This patch
takes care of it.
Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/cxgb3/cxgb3_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index ad19585d960be..f208712c0b90d 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -2296,6 +2296,8 @@ static int cxgb_extension_ioctl(struct net_device *dev, void __user *useraddr)
case CHELSIO_GET_QSET_NUM:{
struct ch_reg edata;
+ memset(&edata, 0, sizeof(struct ch_reg));
+
edata.cmd = CHELSIO_GET_QSET_NUM;
edata.val = pi->nqsets;
if (copy_to_user(useraddr, &edata, sizeof(edata)))
--
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