netdev - [net-next PATCH] ixgbe: fix XDP redirect on archs with PAGE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 28 Feb 2020 13:20:04 +0100
From:   Jesper Dangaard Brouer <brouer@...hat.com>
To:     Jesper Dangaard Brouer <brouer@...hat.com>, netdev@...r.kernel.org
Cc:     John Fastabend <john.fastabend@...il.com>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        intel-wired-lan@...ts.osuosl.org
Subject: [net-next PATCH] ixgbe: fix XDP redirect on archs with PAGE_SIZE
 above 4K

The ixgbe driver have another memory model when compiled on archs with
PAGE_SIZE above 4096 bytes. In this mode it doesn't split the page in
two halves, but instead increment rx_buffer->page_offset by truesize of
packet (which include headroom and tailroom for skb_shared_info).

This is done correctly in ixgbe_build_skb(), but in ixgbe_rx_buffer_flip
which is currently only called on XDP_TX and XDP_REDIRECT, it forgets
to add the tailroom for skb_shared_info. This breaks XDP_REDIRECT, for
veth and cpumap.  Fix by adding size of skb_shared_info tailroom.

Fixes: 6453073987ba ("ixgbe: add initial support for xdp redirect")
Signed-off-by: Jesper Dangaard Brouer <brouer@...hat.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 718931d951bc..ea6834bae04c 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2254,7 +2254,8 @@ static void ixgbe_rx_buffer_flip(struct ixgbe_ring *rx_ring,
 	rx_buffer->page_offset ^= truesize;
 #else
 	unsigned int truesize = ring_uses_build_skb(rx_ring) ?
-				SKB_DATA_ALIGN(IXGBE_SKB_PAD + size) :
+				SKB_DATA_ALIGN(IXGBE_SKB_PAD + size) +
+				SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
 				SKB_DATA_ALIGN(size);

 	rx_buffer->page_offset += truesize;