From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Jesper Dangaard Brouer" <brouer@redhat.com>,
"Mao Wenan" <maowenan@huawei.com>,
"Alexei Starovoitov" <ast@kernel.org>,
"Toshiaki Makita" <toshiaki.makita1@gmail.com>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Sasha Levin" <sashal@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 074/106] veth: Adjust hard_start offset on redirect XDP frames
Date: Mon, 8 Jun 2020 19:22:06 -0400 [thread overview]
Message-ID: <20200608232238.3368589-74-sashal@kernel.org> (raw)
In-Reply-To: <20200608232238.3368589-1-sashal@kernel.org>
From: Jesper Dangaard Brouer <brouer@redhat.com>
[ Upstream commit 5c8572251fabc5bb49fd623c064e95a9daf6a3e3 ]
When native XDP redirect into a veth device, the frame arrives in the
xdp_frame structure. It is then processed in veth_xdp_rcv_one(),
which can run a new XDP bpf_prog on the packet. Doing so requires
converting xdp_frame to xdp_buff, but the tricky part is that
xdp_frame memory area is located in the top (data_hard_start) memory
area that xdp_buff will point into.
The current code tried to protect the xdp_frame area, by assigning
xdp_buff.data_hard_start past this memory. This results in 32 bytes
less headroom to expand into via BPF-helper bpf_xdp_adjust_head().
This protect step is actually not needed, because BPF-helper
bpf_xdp_adjust_head() already reserve this area, and don't allow
BPF-prog to expand into it. Thus, it is safe to point data_hard_start
directly at xdp_frame memory area.
Fixes: 9fc8d518d9d5 ("veth: Handle xdp_frames in xdp napi ring")
Reported-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toshiaki Makita <toshiaki.makita1@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/158945338331.97035.5923525383710752178.stgit@firesoul
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/veth.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 41a00cd76955..2abbad1abaf2 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -377,13 +377,15 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
unsigned int *xdp_xmit)
{
void *hard_start = frame->data - frame->headroom;
- void *head = hard_start - sizeof(struct xdp_frame);
int len = frame->len, delta = 0;
struct xdp_frame orig_frame;
struct bpf_prog *xdp_prog;
unsigned int headroom;
struct sk_buff *skb;
+ /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */
+ hard_start -= sizeof(struct xdp_frame);
+
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
if (likely(xdp_prog)) {
@@ -405,7 +407,6 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
break;
case XDP_TX:
orig_frame = *frame;
- xdp.data_hard_start = head;
xdp.rxq->mem = frame->mem;
if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
trace_xdp_exception(rq->dev, xdp_prog, act);
@@ -417,7 +418,6 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
goto xdp_xmit;
case XDP_REDIRECT:
orig_frame = *frame;
- xdp.data_hard_start = head;
xdp.rxq->mem = frame->mem;
if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
frame = &orig_frame;
@@ -437,7 +437,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
rcu_read_unlock();
headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
- skb = veth_build_skb(head, headroom, len, 0);
+ skb = veth_build_skb(hard_start, headroom, len, 0);
if (!skb) {
xdp_return_frame(frame);
goto err;
--
2.25.1
next prev parent reply other threads:[~2020-06-08 23:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-08 23:20 [PATCH AUTOSEL 4.19 001/106] ath9x: Fix stack-out-of-bounds Write in ath9k_hif_usb_rx_cb Sasha Levin
2020-06-08 23:20 ` [PATCH AUTOSEL 4.19 002/106] ath9k: Fix use-after-free Write in ath9k_htc_rx_msg Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 008/106] net: atlantic: make hw_get_regs optional Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 009/106] net: ena: fix error returning in ena_com_get_hash_function() Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 015/106] ixgbe: Fix XDP redirect on archs with PAGE_SIZE above 4K Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 017/106] Bluetooth: Add SCO fallback for invalid LMP parameters error Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 025/106] batman-adv: Revert "disable ethtool link speed detection when auto negotiation off" Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 029/106] net: vmxnet3: fix possible buffer overflow caused by bad DMA value in vmxnet3_get_rss() Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 031/106] ath9k: Fix use-after-free Read in ath9k_wmi_ctrl_rx Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 032/106] ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 033/106] brcmfmac: fix wrong location to get firmware feature Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 035/106] e1000: Distribute switch variables for initialization Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 043/106] netfilter: nft_nat: return EOPNOTSUPP if type or flags are not supported Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 044/106] selftests/bpf: Fix memory leak in extract_build_id() Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 045/106] net: bcmgenet: set Rx mode before starting netif Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 051/106] net: lpc-enet: fix error return code in lpc_mii_init() Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 053/106] net: allwinner: Fix use correct return type for ndo_start_xmit() Sasha Levin
2020-06-08 23:21 ` [PATCH AUTOSEL 4.19 055/106] ath9k_htc: Silence undersized packet warnings Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 068/106] ath10k: Remove msdu from idr when management pkt send fails Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 069/106] wcn36xx: Fix error handling path in 'wcn36xx_probe()' Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 070/106] net: qed*: Reduce RX and TX default ring count when running inside kdump kernel Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 071/106] mt76: avoid rx reorder buffer overflow Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 073/106] net: dsa: mt7530: set CPU port to fallback mode Sasha Levin
2020-06-08 23:22 ` Sasha Levin [this message]
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 075/106] net/mlx5e: IPoIB, Drop multicast packets that this interface sent Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 076/106] rtlwifi: Fix a double free in _rtl_usb_tx_urb_setup() Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 077/106] mwifiex: Fix memory corruption in dump_station Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 087/106] net: ethernet: fec: move GPR register offset and bit into DT Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 088/106] macvlan: Skip loopback packets in RX handler Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 097/106] ixgbe: fix signed-integer-overflow warning Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 104/106] vxlan: Avoid infinite loop when suppressing NS messages with invalid options Sasha Levin
2020-06-08 23:22 ` [PATCH AUTOSEL 4.19 105/106] net_failover: fixed rollback in net_failover_open() Sasha Levin
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