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author | Cong Wang <xiyou.wangcong@gmail.com> | 2017-11-10 03:43:13 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2017-11-11 13:35:32 +0300 |
commit | 052d41c01b3a2e3371d66de569717353af489d63 (patch) | |
tree | 995570b6b32fea4c07ac142f608f40c6b2baa9fa /drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | |
parent | 2118df93b5e1742931da358c2b8804c46fd64490 (diff) | |
download | linux-052d41c01b3a2e3371d66de569717353af489d63.tar.xz |
vlan: fix a use-after-free in vlan_device_event()
After refcnt reaches zero, vlan_vid_del() could free
dev->vlan_info via RCU:
RCU_INIT_POINTER(dev->vlan_info, NULL);
call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
However, the pointer 'grp' still points to that memory
since it is set before vlan_vid_del():
vlan_info = rtnl_dereference(dev->vlan_info);
if (!vlan_info)
goto out;
grp = &vlan_info->grp;
Depends on when that RCU callback is scheduled, we could
trigger a use-after-free in vlan_group_for_each_dev()
right following this vlan_vid_del().
Fix it by moving vlan_vid_del() before setting grp. This
is also symmetric to the vlan_vid_add() we call in
vlan_device_event().
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: efc73f4bbc23 ("net: Fix memory leak - vlan_info struct")
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Girish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Girish Moodalbail <girish.moodalbail@oracle.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c')
0 files changed, 0 insertions, 0 deletions