From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2BD83D9022; Wed, 25 Mar 2026 13:11:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774444306; cv=none; b=VHNLrqbMniX94IKKsGsss4ilfaXiRX1oaSd59Lmt/hKtinXQBhut3u7BaCf0KNeF6QZYOzORO1jY7S62/kNtlnYWsWHVTZp7gFekDWZW7vHJO7OgFQUKfNeRRdBEl2EeqwelBjQX2dcjlLdGV80Sd+zHp/oUfohPx4Ft9Q7C6p8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774444306; c=relaxed/simple; bh=d04Zfo0BIF6gHy3v4BYuPlJBjVxEQOB7Z3gsWVJVK54=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d0yiGXySbcfb9k5kCoWGXNy30ZhCJxvg/tuJHsfubUYjg7UwxixQ9IhBg0Bbj7nyUVKKtmdzLUzoAexVOYeMCloX3zibIoArUYKIHUr5nc2nD6Yn42peFOs9VamEyFG3eD90SsPoXPmpL/yfnlrb3bPPEZ5B8dKon62kyMTZnm8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id A86E3609EF; Wed, 25 Mar 2026 14:11:37 +0100 (CET) From: Florian Westphal To: Cc: Paolo Abeni , "David S. Miller" , Eric Dumazet , Jakub Kicinski , , pablo@netfilter.org Subject: [PATCH net 01/14] netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry Date: Wed, 25 Mar 2026 14:10:55 +0100 Message-ID: <20260325131108.23045-2-fw@strlen.de> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260325131108.23045-1-fw@strlen.de> References: <20260325131108.23045-1-fw@strlen.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit New test case fails unexpectedly when avx2 matching functions are used. The test first loads a ranomly generated pipapo set with 'ipv4 . port' key, i.e. nft -f foo. This works. Then, it reloads the set after a flush: (echo flush set t s; cat foo) | nft -f - This is expected to work, because its the same set after all and it was already loaded once. But with avx2, this fails: nft reports a clashing element. The reported clash is of following form: We successfully re-inserted a . b c . d Then we try to insert a . d avx2 finds the already existing a . d, which (due to 'flush set') is marked as invalid in the new generation. It skips the element and moves to next. Due to incorrect masking, the skip-step finds the next matching element *only considering the first field*, i.e. we return the already reinserted "a . b", even though the last field is different and the entry should not have been matched. No such error is reported for the generic c implementation (no avx2) or when the last field has to use the 'nft_pipapo_avx2_lookup_slow' fallback. Bisection points to 7711f4bb4b36 ("netfilter: nft_set_pipapo: fix range overlap detection") but that fix merely uncovers this bug. Before this commit, the wrong element is returned, but erronously reported as a full, identical duplicate. The root-cause is too early return in the avx2 match functions. When we process the last field, we should continue to process data until the entire input size has been consumed to make sure no stale bits remain in the map. Reviewed-by: Stefano Brivio Link: https://lore.kernel.org/netfilter-devel/20260321152506.037f68c0@elisabeth/ Signed-off-by: Florian Westphal --- net/netfilter/nft_set_pipapo_avx2.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/net/netfilter/nft_set_pipapo_avx2.c b/net/netfilter/nft_set_pipapo_avx2.c index 7ff90325c97f..6395982e4d95 100644 --- a/net/netfilter/nft_set_pipapo_avx2.c +++ b/net/netfilter/nft_set_pipapo_avx2.c @@ -242,7 +242,7 @@ static int nft_pipapo_avx2_lookup_4b_2(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -319,7 +319,7 @@ static int nft_pipapo_avx2_lookup_4b_4(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -414,7 +414,7 @@ static int nft_pipapo_avx2_lookup_4b_8(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -505,7 +505,7 @@ static int nft_pipapo_avx2_lookup_4b_12(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -641,7 +641,7 @@ static int nft_pipapo_avx2_lookup_4b_32(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -699,7 +699,7 @@ static int nft_pipapo_avx2_lookup_8b_1(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -764,7 +764,7 @@ static int nft_pipapo_avx2_lookup_8b_2(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -839,7 +839,7 @@ static int nft_pipapo_avx2_lookup_8b_4(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -925,7 +925,7 @@ static int nft_pipapo_avx2_lookup_8b_6(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; @@ -1019,7 +1019,7 @@ static int nft_pipapo_avx2_lookup_8b_16(unsigned long *map, unsigned long *fill, b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last); if (last) - return b; + ret = b; if (unlikely(ret == -1)) ret = b / XSAVE_YMM_SIZE; -- 2.52.0