From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (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 E815F3EB10D; Sun, 27 Sep 2026 22:08:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790546918; cv=none; b=qtk9NcvgBl5LlNU4YSV6PeX3jOSPW0Gz23XyrwNnLShjWg7xw18a/q+KK7Yi6GHx36TdOLVAPaK2H6VpTdxZAP3xBLyl+5XMyG9gu2arUzv09/DKAbTCOOt5D1LMsR0ptPVUyta8DK/osEIxpjTl+NNV2MlpTN2aNssugj4xUqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790546918; c=relaxed/simple; bh=x6480Bkp4FMukmxr95Y6+aX959844cxgZnkNbjHndQM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NTkhiiRsWsj0c9XrnriFX7GM+Jk/u9u+FWRf2TLzS1225uJLDo/znWgbEM6gX2Mw2zicv7awA9jbVXRs1Y50YH3tgEzslA9z0Qnrj8LMEnCNaTNq24MDls+rD4rZdMFf9iiQPLA4KPKVs4yLHmcd4wC/XoXaaiBnNUDkAbYEQqA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=LC/40+tS; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="LC/40+tS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1790546911; bh=6l5thKv2kTDA338HhHiKkjI3Rp+ZkGjxPqRXLRQ8F/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LC/40+tSecYW8/9rKtgxXM+vv3dWYYCW1t7/5smFkS/qHKhgPsvkLo6l0beVd2qxN nZVO8Eridl6reh8svQW04dpU0aEodPSLZGm2I50WxRBDIuGtqkpOCsKdO8EGLc6SSF 6JJBnquh7dnxPAP6air6P0QaudGh5c8g7fIeoqeCm8mVzi1BYK6E48uHknao4l10DG 4grbPl5wCVasu+pI7jsnJNuY1S5O0JeeIAo/1b3IZB35ejTdO7+4gIEmtIeivMMdUG CUyX5LRhwmfhwKSlKgca9roncoBRbwgpRAatwoeTRIXQgEgVkJ3vZnNu6AecEVigYB GzFXa3u68Z36A== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 67C6F603E4; Mon, 28 Sep 2026 00:08:31 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, horms@kernel.org, fw@strlen.de, ja@ssi.bg Subject: [PATCH net 08/11] netfilter: nft_set_rbtree: skip transaction elements during GC Date: Mon, 28 Sep 2026 00:08:13 +0200 Message-ID: <20260927220816.268206-9-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260927220816.268206-1-pablo@netfilter.org> References: <20260927220816.268206-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Weiming Shi Since nft_set_commit_update() runs set commit callbacks before processing NEWSETELEM transactions, nft_rbtree_gc_scan() can observe elements added by the transaction being committed. The scan records an interval end in rbe_end without checking the element's transaction state. A later, unrelated expired start then moves both elements to the expired list. The synchronous GC queue can free the new end element before the transaction subsequently activates it, causing a use-after-free. Only consider elements that are fully active in both generations. This keeps transaction-state elements out of the GC scan and preserves interval pairing across skipped elements. KASAN reports: BUG: KASAN: slab-use-after-free in nft_setelem_activate nft_setelem_activate net/netfilter/nf_tables_api.c:7047 nf_tables_commit net/netfilter/nf_tables_api.c:11137 Allocated by task 130: nft_set_elem_init net/netfilter/nf_tables_api.c:6794 nft_add_set_elem net/netfilter/nf_tables_api.c:7523 Freed by task 130: nft_trans_gc_trans_free net/netfilter/nf_tables_api.c:10506 rcu_core kernel/rcu/tree.c:2919 Fixes: 1e3b9e1c77fe ("netfilter: nf_tables: call set ops .commit when building new ruleset blob") Reported-by: Assisted-by: LLM Signed-off-by: Weiming Shi Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_set_rbtree.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 9894832281c4..12431b55752f 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -900,6 +900,8 @@ static void nft_rbtree_gc_scan(struct nft_set *set) next = rb_next(node); rbe = rb_entry(node, struct nft_rbtree_elem, node); + if (!nft_set_elem_active(&rbe->ext, NFT_GENMASK_ANY)) + continue; /* elements are reversed in the rbtree for historical reasons, * from highest to lowest value, that is why end element is -- 2.47.3