[PATCH AUTOSEL 4.19 24/73] liquidio: read sc->iq_no before release sc

Sasha Levin
2018-12-13T04:50:50Z

From: Pan Bian <bianpan2016@163.com>

[ Upstream commit c0f53771ba45745e5870daf880127925c93f232f ]

The function lio_vf_rep_packet_sent_callback releases the occupation of
sc via octeon_free_soft_command. sc should not be used after that.
Unfortunately, sc->iq_no is read. To fix this, the patch stores sc->iq_no
into a local variable before releasing sc and then uses the local variable
instead of sc->iq_no.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c
index ddd7431579f4..c99b59fe4c8f 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c
@@ -367,13 +367,15 @@ lio_vf_rep_packet_sent_callback(struct octeon_device *oct,
struct octeon_soft_command *sc = (struct octeon_soft_command *)buf;
struct sk_buff *skb = sc->ctxptr;
struct net_device *ndev = skb->dev;
+ u32 iq_no;

dma_unmap_single(&oct->pci_dev->dev, sc->dmadptr,
sc->datasize, DMA_TO_DEVICE);
dev_kfree_skb_any(skb);
+ iq_no = sc->iq_no;
octeon_free_soft_command(oct, sc);

- if (octnet_iq_is_full(oct, sc->iq_no))
+ if (octnet_iq_is_full(oct, iq_no))
return;

if (netif_queue_stopped(ndev))
--
2.19.1