Re: [Patch] Fixing order of trinary operator when assigning the ifindex in XFRM Decode Session

Hi Carlos:

patches sent to netdev should be plain text only. Using git send-email would be best.

Also, the Subject line should start with the area affected (e.g., net: xfrm:) and really should be a bit shorter. e.g., something like this:

[PATCH] net: xfrm: fix flow oif in decode_session


On 1/12/17 1:01 PM, Chacon, Carlos A wrote:

Author: Carlos Chacon [off-list ref]
Date:   Thu Jan 12 11:42:32 2017 -0800

    Fixing order of trinary operator when assigning the ifindex in XFRM Decode Session

    For xfrm4_policy.c:_decode_session4 and xfrm6_policy.c:_decode_session6 the line
        fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
        fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
    is assigning the incorrect oif to the flow_oif. It should read:
        reverse ? oif : skb->skb_iif;
    The "reverse" variable is defined in  net/xfrm/xfrm_policy.c:__xfrm_policy_check
    when it checks if the dir is above the XFRM_POLICY_MASK if this returns false
    it reverses the ifindex, but it should only reverse if it returns true.

The above explanation suggests the reverse flag in __xfrm_policy_check should be fixed. Can you check that and maybe __xfrm_policy_check2 as well?