On Wed, Aug 30, 2023 at 12:24 AM Mohamed Khalfella <mkhalfella@xxxxxxxxxxxxxxx> wrote: > > On 2023-08-29 12:09:15 +0200, Eric Dumazet wrote: > > Another way to test this path for certain (without tcpdump having to race) > > is to add a temporary/debug patch like this one: > > > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > > index a298992060e6efdecb87c7ffc8290eafe330583f..20cc42be5e81cdca567515f2a886af4ada0fbe0a > > 100644 > > --- a/net/core/skbuff.c > > +++ b/net/core/skbuff.c > > @@ -1749,7 +1749,8 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) > > int i, order, psize, new_frags; > > u32 d_off; > > > > - if (skb_shared(skb) || skb_unclone(skb, gfp_mask)) > > + if (skb_shared(skb) || > > + pskb_expand_head(skb, 0, 0, gfp_mask)) > > return -EINVAL; > > > > if (!num_frags) > > > > Note that this might catch other bugs :/ > > I was not able to make it allocate a new frags by running tcpdump while > reproing the problem. However, I was able to do it with your patch. I am glad this worked, and looking forward to a v2 of your patch, thanks !
