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 8656230C35C for ; Fri, 29 May 2026 23:55:15 +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=1780098916; cv=none; b=hEf0d5eKA47UvHwUkjuvTIKWz15wW20+VD2WIqEtzQ0Dvo9Ng1eYZ9aIWRuh8l1bugPhRIjNkNK4aQy1jrEIdPZblOgibBdXJ3YMvhoBRkgOO9t3Dr6o7u20YUP4j9/qIiaq6DV8Zf9mugjLS1LYw0z2qtroe8JMxxOb4hUKCdI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780098916; c=relaxed/simple; bh=5J5POAr9ejTdlLjy1DQfPQE22wUR/8PpRfKHnnYpQUw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LbUBCOyNZ1vCDOvltSEB6AH/ijmKn16EqNG+MC/vQ4vPtpxou5oFVuOG0oxsqQJTIhCdDmIF0FdP7cjqI6zjd0Avas+ZajOwXRXP0nGKy9ZmqC6bpXGPqxAybx/9GzOikMymNYV2KEgmGJKGDMMUS+59+9xWrgR8F884NZD56Eo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Sd/xGbxx; 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="Sd/xGbxx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2FB21F00893; Fri, 29 May 2026 23:55:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780098915; bh=cnLfbRCfs/OAg+OvCFYW/qAe72x0q5dTfktLtn0KTfA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Sd/xGbxxoHzmUYnOLDeZB8MywgsebEO3Zy2cOnXQ5KrDej3LZeBqcK4WakStxY9qO 71vdAulP6fWbXIuPSx0agIj99keYzIuaQY6Fa6tiw4LSm4QG6pMgit/c7uzBbnV2cn KVs9BOe97Bh+WKLJ+sKvlXATLkCqrpw7P3Si3Une66InThTa9mNBtDJKkAop3u9L1C pWY7KZTXrZSfSUzaOhUB9/ZyLxoUMl+TrOZQ84stHp6UtS+SnXFxiNdjDA9vE5ugp0 soHftDU1zXYrI/Y5uK+zr8XBHHfL6y2cnenWT/pzojExCgbYluFVna74FNhP00PuFZ 0vR1PmD1cfGWw== From: Sasha Levin To: stable@vger.kernel.org Cc: Michael Bommarito , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1.y] net: hsr: defer node table free until after RCU readers Date: Fri, 29 May 2026 19:55:12 -0400 Message-ID: <20260529235512.1985956-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026052840-statistic-envoy-e450@gregkh> References: <2026052840-statistic-envoy-e450@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 e44a039e36afe..fec8dd8460568 100644 --- a/net/hsr/hsr_framereg.c +++ b/net/hsr/hsr_framereg.c @@ -121,8 +121,10 @@ 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