netfilter: xt_cpu: prefer raw_smp_processor_id

With PREEMPT_RCU we get splat:

BUG: using smp_processor_id() in preemptible [..]
caller is cpu_mt+0x53/0xd0 net/netfilter/xt_cpu.c:37
CPU: 1 .. Comm: syz.3.1377 #0 PREEMPT(full)
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 check_preemption_disabled+0xd3/0xe0 lib/smp_processor_id.c:47
 cpu_mt+0x53/0xd0 net/netfilter/xt_cpu.c:37
 [..]

Just use raw version instead.
This is similar to 14d14a5d29 ("netfilter: nft_meta: use raw_smp_processor_id()").

Fixes: 0ca743a559 ("netfilter: nf_tables: add compatibility layer for x_tables")
Reported-by: syzbot+690d3e3ffa7335ac10eb@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
This commit is contained in:
Florian Westphal 2026-05-19 20:10:08 +02:00
parent 47980b6dbf
commit c376f07e16

View File

@ -34,7 +34,7 @@ static bool cpu_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_cpu_info *info = par->matchinfo;
return (info->cpu == smp_processor_id()) ^ info->invert;
return (info->cpu == raw_smp_processor_id()) ^ info->invert;
}
static struct xt_match cpu_mt_reg __read_mostly = {