On Thu, Jul 18, 2024 at 10:56 AM Corinna Vinschen <[email protected]> wrote: > > From: Paolo Abeni <[email protected]> > > Sabrina reports that the igb driver does not cope well with large > MAX_SKB_FRAG values: setting MAX_SKB_FRAG to 45 causes payload > corruption on TX. > > An easy reproducer is to run ssh to connect to the machine. With > MAX_SKB_FRAGS=17 it works, with MAX_SKB_FRAGS=45 it fails. > > The root cause of the issue is that the driver does not take into > account properly the (possibly large) shared info size when selecting > the ring layout, and will try to fit two packets inside the same 4K > page even when the 1st fraglist will trump over the 2nd head. > > Address the issue forcing the driver to fit a single packet per page, > leaving there enough room to store the (currently) largest possible > skb_shared_info. > > Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAGS") > Reported-by: Jan Tluka <[email protected]> > Reported-by: Jirka Hladky <[email protected]> > Reported-by: Sabrina Dubroca <[email protected]> > Tested-by: Sabrina Dubroca <[email protected]> > Tested-by: Corinna Vinschen <[email protected]> > Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
