On Mon, Feb 3, 2020 at 4:16 AM Florian Westphal <fw@xxxxxxxxx> wrote: > > Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote: > > The hashtable size could be controlled by user, so use flags > > GFP_USER | __GFP_NOWARN to avoid OOM warning triggered by user-space. > > > > Also add __GFP_NORETRY to avoid retrying, as this is just a > > best effort and the failure is already handled gracefully. > > > > Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@xxxxxxxxxxxxxxxxxxxxxxxxx > > Cc: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> > > Cc: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx> > > Cc: Florian Westphal <fw@xxxxxxxxx> > > Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> > > --- > > net/netfilter/xt_hashlimit.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c > > index bccd47cd7190..5d9943b37c42 100644 > > --- a/net/netfilter/xt_hashlimit.c > > +++ b/net/netfilter/xt_hashlimit.c > > @@ -293,8 +293,8 @@ static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg, > > if (size < 16) > > size = 16; > > } > > - /* FIXME: don't use vmalloc() here or anywhere else -HW */ > > - hinfo = vmalloc(struct_size(hinfo, hash, size)); > > + hinfo = __vmalloc(struct_size(hinfo, hash, size), > > + GFP_USER | __GFP_NOWARN | __GFP_NORETRY, PAGE_KERNEL); > > Sorry for not noticing this earlier: should that be GFP_KERNEL_ACCOUNT > instead of GFP_USER? Why do you think it should be accounted in kmemcg? I think this one is controlled by user, so I pick GFP_USER, like many other cases, for example, proc_allowed_congestion_control(). GFP_KERNEL_ACCOUNT (or SLAB_ACCOUNT) is not common in networking, it is typically for socket allocations. GFP_USER is common. Thanks.
