Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 90fa1b38 authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman
Browse files

net: usb: smsc95xx: stop lying about skb->truesize 

[ Upstream commit d50729f1d60bca822ef6d9c1a5fb28d486bd7593 ]

Some usb drivers try to set small skb->truesize and break
core networking stacks.

In this patch, I removed one of the skb->truesize override.

I also replaced one skb_clone() by an allocation of a fresh
and small skb, to get minimally sized skbs, like we did
in commit 1e2c6117 ("net: cdc_ncm: reduce skb truesize
in rx path") and 4ce62d5b2f7a ("net: usb: ax88179_178a:
stop lying about skb->truesize")

v3: also fix a sparse error ( https://lore.kernel.org/oe-kbuild-all/202405091310.KvncIecx-lkp@intel.com/

 )
v2: leave the skb_trim() game because smsc95xx_rx_csum_offload()
    needs the csum part. (Jakub)
    While we are it, use get_unaligned() in smsc95xx_rx_csum_offload().

Fixes: 2f7ca802 ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
Cc: UNGLinuxDriver@microchip.com
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240509083313.2113832-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent de6641d2

drivers/net/usb/smsc95xx.c

+7 −8
Original line number Diff line number Diff line
@@ -1910,9 +1910,11 @@ static int smsc95xx_reset_resume(struct usb_interface *intf) 


static void smsc95xx_rx_csum_offload(struct sk_buff *skb)

{

	skb->csum = *(u16 *)(skb_tail_pointer(skb) - 2);

	u16 *csum_ptr = (u16 *)(skb_tail_pointer(skb) - 2);



	skb->csum = (__force __wsum)get_unaligned(csum_ptr);

	skb->ip_summed = CHECKSUM_COMPLETE;

	skb_trim(skb, skb->len - 2);

	skb_trim(skb, skb->len - 2); /* remove csum */

}



static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
@@ -1970,25 +1972,22 @@ static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 
				if (dev->net->features & NETIF_F_RXCSUM)

					smsc95xx_rx_csum_offload(skb);

				skb_trim(skb, skb->len - 4); /* remove fcs */

				skb->truesize = size + sizeof(struct sk_buff);



				return 1;

			}



			ax_skb = skb_clone(skb, GFP_ATOMIC);

			ax_skb = netdev_alloc_skb_ip_align(dev->net, size);

			if (unlikely(!ax_skb)) {

				netdev_warn(dev->net, "Error allocating skb\n");

				return 0;

			}



			ax_skb->len = size;

			ax_skb->data = packet;

			skb_set_tail_pointer(ax_skb, size);

			skb_put(ax_skb, size);

			memcpy(ax_skb->data, packet, size);



			if (dev->net->features & NETIF_F_RXCSUM)

				smsc95xx_rx_csum_offload(ax_skb);

			skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */

			ax_skb->truesize = size + sizeof(struct sk_buff);



			usbnet_skb_return(dev, ax_skb);

		}