| Message ID | 20230522190713.82417-1-tbogendoerfer@suse.de (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] net: mellanox: mlxbf_gige: Fix skb_panic splat under memory pressure | expand |
On Mon, 22 May 2023 21:07:13 +0200 Thomas Bogendoerfer wrote: > Do skp_put() after a new skb has been successfully allocated otherwise > the reused skb leads to skp_panics or incorrect packet sizes. s/skp/skb/ Please add a Fixes tag pointing at the patch which introduced the problem (could be the first commit adding this driver). > Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de> > --- > .../ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c > index afa3b92a6905..2c132849a76d 100644 > --- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c > +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c > @@ -245,18 +245,19 @@ static bool mlxbf_gige_rx_packet(struct mlxbf_gige *priv, int *rx_pkts) > > skb = priv->rx_skb[rx_pi_rem]; > > - skb_put(skb, datalen); > - > - skb->ip_summed = CHECKSUM_NONE; /* device did not checksum packet */ > - > - skb->protocol = eth_type_trans(skb, netdev); > - > /* Alloc another RX SKB for this same index */ > rx_skb = mlxbf_gige_alloc_skb(priv, MLXBF_GIGE_DEFAULT_BUF_SZ, > &rx_buf_dma, DMA_FROM_DEVICE); > if (!rx_skb) > return false; > priv->rx_skb[rx_pi_rem] = rx_skb; > + > + skb_put(skb, datalen); > + > + skb->ip_summed = CHECKSUM_NONE; /* device did not checksum packet */ > + > + skb->protocol = eth_type_trans(skb, netdev); > > dma_unmap_single(priv->dev, *rx_wqe_addr, > MLXBF_GIGE_DEFAULT_BUF_SZ, DMA_FROM_DEVICE); You should move the code here, after the dma_unmap(). eth_type_trans() will access the payload and until dma_unmap the data should not be accessed by the CPU. > *rx_wqe_addr = rx_buf_dma;
diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c index afa3b92a6905..2c132849a76d 100644 --- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c @@ -245,18 +245,19 @@ static bool mlxbf_gige_rx_packet(struct mlxbf_gige *priv, int *rx_pkts) skb = priv->rx_skb[rx_pi_rem]; - skb_put(skb, datalen); - - skb->ip_summed = CHECKSUM_NONE; /* device did not checksum packet */ - - skb->protocol = eth_type_trans(skb, netdev); - /* Alloc another RX SKB for this same index */ rx_skb = mlxbf_gige_alloc_skb(priv, MLXBF_GIGE_DEFAULT_BUF_SZ, &rx_buf_dma, DMA_FROM_DEVICE); if (!rx_skb) return false; priv->rx_skb[rx_pi_rem] = rx_skb; + + skb_put(skb, datalen); + + skb->ip_summed = CHECKSUM_NONE; /* device did not checksum packet */ + + skb->protocol = eth_type_trans(skb, netdev); + dma_unmap_single(priv->dev, *rx_wqe_addr, MLXBF_GIGE_DEFAULT_BUF_SZ, DMA_FROM_DEVICE); *rx_wqe_addr = rx_buf_dma;
Do skp_put() after a new skb has been successfully allocated otherwise the reused skb leads to skp_panics or incorrect packet sizes. Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de> --- .../ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)