On 15/07/2026 10:42, Weijie Gao wrote: > LwIP may pass a packet to the netif linkoutput callback as a chain > of pbufs. In this case, p->len only describes the length of the > first pbuf, while p->tot_len describes the length of the whole > packet. > > The current transmit path only sends the first pbuf. This can > truncate packets whose headers have already been generated for the > full packet length, resulting in malformed frames on the wire. > For example, the IP header may record a larger total length than the > actual Ethernet frame length. > > Assemble chained pbufs into one aligned contiguous buffer before > passing the packet to the Ethernet driver. > > Fixes: 98ad145db61a (net: lwip: add DHCP support and dhcp commmand) > Signed-off-by: Weijie Gao <[email protected]>
Good catch! That was a big oversight :-/ thanks for the fix. Reviewed-by: Jerome Forissier <[email protected]> -- Jerome
