Commit 0a819ba2 authored Feb 14, 2020 by Pavel Belous Committed by Greg Kroah-Hartman Mar 05, 2020

net: atlantic: fix use after free kasan warn



commit a4980919ad6a7be548d499bc5338015e1a9191c6 upstream.

skb->len is used to calculate statistics after xmit invocation.

Under a stress load it may happen that skb will be xmited,
rx interrupt will come and skb will be freed, all before xmit function
is even returned.

Eventually, skb->len will access unallocated area.

Moving stats calculation into tx_clean routine.

Fixes: 018423e9 ("net: ethernet: aquantia: Add ring support code")
Reported-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Pavel Belous <pbelous@marvell.com>
Signed-off-by: Dmitry Bogdanov <dbogdanov@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 0ededb6e

drivers/net/ethernet/aquantia/atlantic/aq_nic.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -530,10 +530,6 @@ int aq_nic_xmit(struct aq_nic_s self, struct sk_buff skb)
		if (likely(frags)) {
		err = self->aq_hw_ops->hw_ring_tx_xmit(self->aq_hw,
		ring, frags);
		if (err >= 0) {
		++ring->stats.tx.packets;
		ring->stats.tx.bytes += skb->len;
		}
		} else {
		err = NETDEV_TX_BUSY;
		}

drivers/net/ethernet/aquantia/atlantic/aq_ring.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -162,9 +162,12 @@ bool aq_ring_tx_clean(struct aq_ring_s *self)
		}
		}

		if (unlikely(buff->is_eop))
		dev_kfree_skb_any(buff->skb);
		if (unlikely(buff->is_eop)) {
		++self->stats.rx.packets;
		self->stats.tx.bytes += buff->skb->len;

		dev_kfree_skb_any(buff->skb);
		}
		buff->pa = 0U;
		buff->eop_index = 0xffffU;
		self->sw_head = aq_ring_next_dx(self, self->sw_head);