[PATCH 4.19 26/67] liquidio: read sc->iq_no before release sc

From: Greg Kroah-Hartman
Date: Thu Dec 20 2018 - 04:32:27 EST

4.19-stable review patch. If anyone has any objections, please let me know.


[ 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@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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);
+ 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))

if (netif_queue_stopped(ndev))