From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2209479DA for ; Sat, 30 May 2026 00:07:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780099658; cv=none; b=mPq5UEsbNq9OxwltrdGf3IkWmv/t/eUlVcjX9lGW3cv3RVXFt02Jr7YLiKozTWW3cAzsR7xf28OalH30u+Wnulcc1Z+8LRL8u0DA5JGZb1EIFQzz+dqQnQ1KctjVs4GPf+Hlf6PW2jqZGBgRsQsAJdg/VE91rwxTAQmdIr/GPVE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780099658; c=relaxed/simple; bh=Nf0gC+nUI0o247QQy39MxQAavm4EqB30b/69xAJIWHk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ue8P5LlnqdtfBAzsQx23fmnKAICTNhnlipXGJ1hhMyDFbJCdhLBcuw8tqU84HkISAEmdoLTmYBAYRDo1T0t1QCYqLQ3znmQEgKweaDHO1zXCLCjRNAy+jEd5rTOs/w8BtBu0OfM2ZNr0JG59bS/EIjk/ezi8Ny3c9vyW8ZNsyjA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HuoIoqA9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HuoIoqA9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A66E1F00893; Sat, 30 May 2026 00:07:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780099656; bh=aZ8hmM9nAVbgoOpLD6uItGZeQBHho8n8QLcIS4n9O4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HuoIoqA9vZy4tXFz5eQBIIZ/h2Cv2ltu5WJIFTWRgY2yeio8D973GYCHnV2vcC+q3 HEQuFTIHXFn6wJ5Ou4Ha8vUm9ss17XSWFxp/ss0Wuo+lSpXg67bxeOMa8EuymSbX6K DIY+3vPkG40M4dvl22TvMSxYmAOxV30tlzeD93cJFWJfFcZSL2C9jjtVPm9/iBM76s sgwgd9uyId7m5Yr3n4J+OGCp9N3ldNuIUlriirN6wpvW/XJxvdRSULHoaR/bKpGgx0 g+dXlMTz9DR5XeNAHlKPI9His3MIqKBIscWsI6W+bU4McHtD2XSNeJ7Y2bfs8HNK+v h34lszi754OMg== From: Sasha Levin To: stable@vger.kernel.org Cc: Michael Bommarito , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15.y] net: hsr: defer node table free until after RCU readers Date: Fri, 29 May 2026 20:07:34 -0400 Message-ID: <20260530000734.2087399-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026052841-straggler-greeting-f0cf@gregkh> References: <2026052841-straggler-greeting-f0cf@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Michael Bommarito [ Upstream commit aaec7096f9961eb223b5b149abe9495525c205d9 ] HSR node-list and node-status generic-netlink operations run under rcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and hsr_get_node_data(), but RTM_DELLINK teardown removes the same node table with plain list_del() and frees each node immediately. That lets a generic-netlink reader hold a struct hsr_node pointer across hsr_dellink(). In a KASAN build, widening the reader window after hsr_get_next_node() obtains the node reproduces a slab-use-after-free when the reader copies node->macaddress_A; the freeing stack is hsr_del_nodes() from hsr_dellink(). Use list_del_rcu() and defer the free through the existing hsr_free_node_rcu() callback. This matches the lifetime rule used by the HSR prune paths, which already delete nodes with list_del_rcu() and call_rcu(). Fixes: b9a1e627405d ("hsr: implement dellink to clean up resources") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260513233838.3064715-2-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski [ replaced `list_del`+`call_rcu(hsr_free_node_rcu)` with `list_del_rcu`+`kfree_rcu(node, rcu_head)` ] Signed-off-by: Sasha Levin --- net/hsr/hsr_framereg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c index e0aeeeda3c876..0b3d9dfbe6d6c 100644 --- a/net/hsr/hsr_framereg.c +++ b/net/hsr/hsr_framereg.c @@ -123,8 +123,10 @@ void hsr_del_nodes(struct list_head *node_db) struct hsr_node *node; struct hsr_node *tmp; - list_for_each_entry_safe(node, tmp, node_db, mac_list) - kfree(node); + list_for_each_entry_safe(node, tmp, node_db, mac_list) { + list_del_rcu(&node->mac_list); + kfree_rcu(node, rcu_head); + } } void prp_handle_san_frame(bool san, enum hsr_port_type port, -- 2.53.0