On Fri, Nov 22, 2024 at 02:45:29PM +0100, Florian Westphal wrote: > Pei Xiao <xiaopei01@xxxxxxxxxx> wrote: > > syzbot complain about using smp_processor_id in preemptible. > > use get_cpu_ptr to preempt_disable. > > > Reported-by: syzbot+84d0441b9860f0d63285@xxxxxxxxxxxxxxxxxxxxxxxxx > > Closes: https://syzkaller.appspot.com/bug?extid=84d0441b9860f0d63285 > > Fixes: 0e795b37ba04 ("netfilter: nft_inner: add percpu inner context") > > Signed-off-by: Pei Xiao <xiaopei01@xxxxxxxxxx> > > --- > > net/netfilter/nft_inner.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/netfilter/nft_inner.c b/net/netfilter/nft_inner.c > > index 928312d01eb1..ae85851bab77 100644 > > --- a/net/netfilter/nft_inner.c > > +++ b/net/netfilter/nft_inner.c > > @@ -248,7 +248,7 @@ static bool nft_inner_parse_needed(const struct nft_inner *priv, > > static void nft_inner_eval(const struct nft_expr *expr, struct nft_regs *regs, > > const struct nft_pktinfo *pkt) > > { > > - struct nft_inner_tun_ctx *tun_ctx = this_cpu_ptr(&nft_pcpu_tun_ctx); > > + struct nft_inner_tun_ctx *tun_ctx = get_cpu_ptr(&nft_pcpu_tun_ctx); > > const struct nft_inner *priv = nft_expr_priv(expr); > > This can't be right, where is it re-enabled? > > Not related to your patch: > Why is this percpu? How is this softirq safe? I can add an owner skbuff to nft_inner_tun_ctx area, so this information can be canceled in case of softirq interference, then trigger a reparsing of the header.
