net/mlx5e: Fix slab-out-of-bounds in mlx5e_rep_is_lag_netdev
authorRaed Salem <raeds@mellanox.com>
Thu, 9 Jul 2020 12:51:53 +0000 (15:51 +0300)
committerSaeed Mahameed <saeedm@mellanox.com>
Tue, 28 Jul 2020 19:55:45 +0000 (12:55 -0700)
commit21083309cab1a66877b410cd61340b5dd7cf4875
treec6a73ede8cd7fdfdcb1d5d244df2bb2f9f5306c7
parent071995c877a8646209d55ff8edddd2b054e7424c
net/mlx5e: Fix slab-out-of-bounds in mlx5e_rep_is_lag_netdev

mlx5e_rep_is_lag_netdev is used as first check as part of netdev events
handler for bond device of non-uplink representors, this handler can get
any netdevice under the same network namespace of mlx5e netdevice. Current
code treats the netdev as mlx5e netdev and only later on verifies this,
hence causes the following Kasan trace:
[15402.744990] ==================================================================
[15402.746942] BUG: KASAN: slab-out-of-bounds in mlx5e_rep_is_lag_netdev+0xcb/0xf0 [mlx5_core]
[15402.749009] Read of size 8 at addr ffff880391f3f6b0 by task ovs-vswitchd/5347

[15402.752065] CPU: 7 PID: 5347 Comm: ovs-vswitchd Kdump: loaded Tainted: G    B      O     --------- -t - 4.18.0-g3dcc204d291d-dirty #1
[15402.755349] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[15402.757600] Call Trace:
[15402.758968]  dump_stack+0x71/0xab
[15402.760427]  print_address_description+0x6a/0x270
[15402.761969]  kasan_report+0x179/0x2d0
[15402.763445]  ? mlx5e_rep_is_lag_netdev+0xcb/0xf0 [mlx5_core]
[15402.765121]  mlx5e_rep_is_lag_netdev+0xcb/0xf0 [mlx5_core]
[15402.766782]  mlx5e_rep_esw_bond_netevent+0x129/0x620 [mlx5_core]

Fix by deferring the violating access to be post the netdev verify check.

Fixes: 7e51891a237f ("net/mlx5e: Use netdev events to set/del egress acl forward-to-vport rule")
Signed-off-by: Raed Salem <raeds@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Vu Pham <vuhuong@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
drivers/net/ethernet/mellanox/mlx5/core/en/rep/bond.c