Commit a16909ae authored Jul 19, 2024 by Florian Westphal Committed by Pablo Neira Ayuso Jul 24, 2024

netfilter: nft_set_pipapo_avx2: disable softinterrupts



We need to disable softinterrupts, else we get following problem:

1. pipapo_avx2 called from process context; fpu usable
2. preempt_disable() called, pcpu scratchmap in use
3. softirq handles rx or tx, we re-enter pipapo_avx2
4. fpu busy, fallback to generic non-avx version
5. fallback reuses scratch map and index, which are in use
   by the preempted process

Handle this same way as generic version by first disabling
softinterrupts while the scratchmap is in use.

Fixes: f0b3d338 ("netfilter: nft_set_pipapo_avx2: Add irq_fpu_usable() check, fallback to non-AVX2 version")
Cc: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent 3ba359c0

net/netfilter/nft_set_pipapo_avx2.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -1139,8 +1139,14 @@ bool nft_pipapo_avx2_lookup(const struct net net, const struct nft_set set,
		bool map_index;
		int i, ret = 0;

		if (unlikely(!irq_fpu_usable()))
		return nft_pipapo_lookup(net, set, key, ext);
		local_bh_disable();

		if (unlikely(!irq_fpu_usable())) {
		bool fallback_res = nft_pipapo_lookup(net, set, key, ext);

		local_bh_enable();
		return fallback_res;
		}

		m = rcu_dereference(priv->match);

		@@ -1155,6 +1161,7 @@ bool nft_pipapo_avx2_lookup(const struct net net, const struct nft_set set,
		scratch = *raw_cpu_ptr(m->scratch);
		if (unlikely(!scratch)) {
		kernel_fpu_end();
		local_bh_enable();
		return false;
		}

		@@ -1235,6 +1242,7 @@ bool nft_pipapo_avx2_lookup(const struct net net, const struct nft_set set,
		if (i % 2)
		scratch->map_index = !map_index;
		kernel_fpu_end();
		local_bh_enable();

		return ret >= 0;
		}