| Message ID | 804e05fe4615cfd51f0cc72307f578ea34a701b4.1732281838.git.xiaopei01@kylinos.cn (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | netfilter: nf_tables: Use get_cpu_ptr in nft_inner_eval | expand |
Pei Xiao <xiaopei01@kylinos.cn> wrote: > syzbot complain about using smp_processor_id in preemptible. > use get_cpu_ptr to preempt_disable. > Reported-by: syzbot+84d0441b9860f0d63285@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=84d0441b9860f0d63285 > Fixes: 0e795b37ba04 ("netfilter: nft_inner: add percpu inner context") > Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn> > --- > 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?
On Fri, Nov 22, 2024 at 02:45:29PM +0100, Florian Westphal wrote: > Pei Xiao <xiaopei01@kylinos.cn> wrote: > > syzbot complain about using smp_processor_id in preemptible. > > use get_cpu_ptr to preempt_disable. > > > Reported-by: syzbot+84d0441b9860f0d63285@syzkaller.appspotmail.com > > Closes: https://syzkaller.appspot.com/bug?extid=84d0441b9860f0d63285 > > Fixes: 0e795b37ba04 ("netfilter: nft_inner: add percpu inner context") > > Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn> > > --- > > 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.
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); if (nft_payload_inner_offset(pkt) < 0)
syzbot complain about using smp_processor_id in preemptible. use get_cpu_ptr to preempt_disable. BUG: using smp_processor_id() in preemptible [00000000] code: syz.3.1627/12102 caller is nft_inner_eval+0xda/0x18e0 net/netfilter/nft_inner.c:251 CPU: 1 UID: 0 PID: 12102 Comm: syz.3.1627 Not tainted 6.12.0-syzkaller-03657-g43fb83c17ba2 #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 check_preemption_disabled+0x10e/0x120 lib/smp_processor_id.c:49 nft_inner_eval+0xda/0x18e0 net/netfilter/nft_inner.c:251 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x202/0x320 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook+0x2c4/0x450 include/linux/netfilter.h:269 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip_output+0x185/0x230 net/ipv4/ip_output.c:434 ip_local_out net/ipv4/ip_output.c:130 [inline] ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1496 udp_send_skb+0xab6/0x1630 net/ipv4/udp.c:984 udp_sendmsg+0x1c21/0x2a60 net/ipv4/udp.c:1272 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2581 ___sys_sendmsg net/socket.c:2635 [inline] __sys_sendmmsg+0x36a/0x720 net/socket.c:2724 __do_sys_sendmmsg net/socket.c:2751 [inline] __se_sys_sendmmsg net/socket.c:2748 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2748 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-by: syzbot+84d0441b9860f0d63285@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=84d0441b9860f0d63285 Fixes: 0e795b37ba04 ("netfilter: nft_inner: add percpu inner context") Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn> --- net/netfilter/nft_inner.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)