| Message ID | 20231104-gemini-largeframe-fix-v1-3-9c5513f22f33@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix large frames in the Gemini ethernet driver | expand |
On Sat, Nov 04, 2023 at 01:43:50PM +0100, Linus Walleij wrote: > The max size of a transfer no matter the MTU is 64KB-1 so immediately > bail out if the skb exceeds that. > > Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet") > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > drivers/net/ethernet/cortina/gemini.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c > index fd08f098850b..23723c9c0f93 100644 > --- a/drivers/net/ethernet/cortina/gemini.c > +++ b/drivers/net/ethernet/cortina/gemini.c > @@ -1156,6 +1156,12 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, > mtu = MTU_SIZE_BIT_MASK; > } > > + if (skb->len > 65535) { > + /* The field for length is only 16 bits */ > + netdev_err(netdev, "%s: frame too big, max size 65535 bytes\n", __func__); > + return -EINVAL; > + } > + The caller of gmac_map_tx_bufs() is a but funky: if (gmac_map_tx_bufs(netdev, skb, txq, &w)) { if (skb_linearize(skb)) goto out_drop; u64_stats_update_begin(&port->tx_stats_syncp); port->tx_frags_linearized++; u64_stats_update_end(&port->tx_stats_syncp); if (gmac_map_tx_bufs(netdev, skb, txq, &w)) goto out_drop_free; } So return -EINVAL is going to cause the skb to be linearised, and then re-tried. Maybe you want to check the error code here, and go straight to out_drop? Andrew
diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c index fd08f098850b..23723c9c0f93 100644 --- a/drivers/net/ethernet/cortina/gemini.c +++ b/drivers/net/ethernet/cortina/gemini.c @@ -1156,6 +1156,12 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, mtu = MTU_SIZE_BIT_MASK; } + if (skb->len > 65535) { + /* The field for length is only 16 bits */ + netdev_err(netdev, "%s: frame too big, max size 65535 bytes\n", __func__); + return -EINVAL; + } + word1 = skb->len; word3 = SOF_BIT;
The max size of a transfer no matter the MTU is 64KB-1 so immediately bail out if the skb exceeds that. Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- drivers/net/ethernet/cortina/gemini.c | 6 ++++++ 1 file changed, 6 insertions(+)