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From:   Konstantin Khorenko <khorenko@virtuozzo.com>
To:     Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc:     Konstantin Khorenko <khorenko@virtuozzo.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        intel-wired-lan@lists.osuosl.org,
        "David S . Miller" <davem@davemloft.net>
Subject: [PATCH 1/1] drivers/net/i40e: define proper net_device::neigh_priv_len
Date:   Fri, 23 Nov 2018 19:10:28 +0300
Message-Id: <20181123161028.22633-2-khorenko@virtuozzo.com>
In-Reply-To: <20181123161028.22633-1-khorenko@virtuozzo.com>
References: <20181123161028.22633-1-khorenko@virtuozzo.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Out of bound read reported by KASan.

i40iw_net_event() reads unconditionally 16 bytes from
neigh->primary_key while the memory allocated for
"neighbour" struct is evaluated in neigh_alloc() as

  tbl->entry_size + dev->neigh_priv_len

where "dev" is a net_device.

But the driver does not setup dev->neigh_priv_len and
we read beyond the neigh entry allocated memory,
so the patch in the next mail fixes this.

Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 21c2688d6308..539b8f3738e6 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -12334,6 +12334,9 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 	ether_addr_copy(netdev->dev_addr, mac_addr);
 	ether_addr_copy(netdev->perm_addr, mac_addr);
 
+	/* i40iw_net_event() reads 16 bytes from neigh->primary_key */
+	netdev->neigh_priv_len = sizeof(u32) * 4;
+
 	netdev->priv_flags |= IFF_UNICAST_FLT;
 	netdev->priv_flags |= IFF_SUPP_NOFCS;
 	/* Setup netdev TC information */
-- 
2.15.1