4.19-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ 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 1e2c61172342 ("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: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver") Signed-off-by: Eric Dumazet edumazet@google.com Cc: Steve Glendinning steve.glendinning@shawell.net Cc: UNGLinuxDriver@microchip.com Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/20240509083313.2113832-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/smsc95xx.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 37547ac72840f..be5543c71d069 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -1924,9 +1924,11 @@ 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) @@ -1985,25 +1987,22 @@ 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); }