From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 21C99C129; Mon, 1 Apr 2024 16:23:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711988594; cv=none; b=HNUeU63V91lvR1MhqLX4NBBWKoEUVL+RsZj2LaLfYFneoky56c+//rBE5935n1GPGOYK/60WE0itC70wTC+lP167EiuTwemVjvKbYmvKYACjyS202Lm3Ner4/dyBFVJXnHtSUsqARAUmBpTDsEwq07haghTh52yFXNul41P2Bq8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711988594; c=relaxed/simple; bh=CJBdm/QALX3cyQUgyoUEtjLjTDSQH9JWAi41OcenZ1w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QqOoQ7OZ4yAlr+iw9fheCDY/kDgSS6hD5SBJcRc13hfqxXv1V8tZnQipkDM/Ce8IgLQBMbz7UbtuLDPxitdaUB9a0YZMQmgQErqM3Vg+RqmxShB4zaf+dnQds9LANoFxMOyhL7XvAgCe9vc5mds9ReUaAjJ+lAEBkQLUSpz4Lw0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OX6iNdT9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OX6iNdT9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84CA2C433C7; Mon, 1 Apr 2024 16:23:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711988594; bh=CJBdm/QALX3cyQUgyoUEtjLjTDSQH9JWAi41OcenZ1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OX6iNdT9Mu7DXu9/HhtzWPzoi+AUtOqIovvJsIyvQWQbMmoAEQmdgyVxMTvP8PzWR Ub48FI5gA7uidFkMFMlbenUaaIbN6lDYglvCZA2nVopflBeDSJ2nTQfOWihtsHuOvm /bIRnhFnA+eccNMTtJO5U/FmvV0z6nsiU09InHOs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lillian Berry , "Jason A. Donenfeld" , Jiri Pirko , Paolo Abeni , Sasha Levin Subject: [PATCH 6.7 202/432] wireguard: netlink: check for dangling peer via is_dead instead of empty list Date: Mon, 1 Apr 2024 17:43:09 +0200 Message-ID: <20240401152559.161733396@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240401152553.125349965@linuxfoundation.org> References: <20240401152553.125349965@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason A. Donenfeld [ Upstream commit 55b6c738673871c9b0edae05d0c97995c1ff08c4 ] If all peers are removed via wg_peer_remove_all(), rather than setting peer_list to empty, the peer is added to a temporary list with a head on the stack of wg_peer_remove_all(). If a netlink dump is resumed and the cursored peer is one that has been removed via wg_peer_remove_all(), it will iterate from that peer and then attempt to dump freed peers. Fix this by instead checking peer->is_dead, which was explictly created for this purpose. Also move up the device_update_lock lockdep assertion, since reading is_dead relies on that. It can be reproduced by a small script like: echo "Setting config..." ip link add dev wg0 type wireguard wg setconf wg0 /big-config ( while true; do echo "Showing config..." wg showconf wg0 > /dev/null done ) & sleep 4 wg setconf wg0 <(printf "[Peer]\nPublicKey=$(wg genkey)\n") Resulting in: BUG: KASAN: slab-use-after-free in __lock_acquire+0x182a/0x1b20 Read of size 8 at addr ffff88811956ec70 by task wg/59 CPU: 2 PID: 59 Comm: wg Not tainted 6.8.0-rc2-debug+ #5 Call Trace: dump_stack_lvl+0x47/0x70 print_address_description.constprop.0+0x2c/0x380 print_report+0xab/0x250 kasan_report+0xba/0xf0 __lock_acquire+0x182a/0x1b20 lock_acquire+0x191/0x4b0 down_read+0x80/0x440 get_peer+0x140/0xcb0 wg_get_device_dump+0x471/0x1130 Cc: stable@vger.kernel.org Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Reported-by: Lillian Berry Signed-off-by: Jason A. Donenfeld Reviewed-by: Jiri Pirko Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/wireguard/netlink.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c index e220d761b1f27..c17aee454fa3b 100644 --- a/drivers/net/wireguard/netlink.c +++ b/drivers/net/wireguard/netlink.c @@ -255,17 +255,17 @@ static int wg_get_device_dump(struct sk_buff *skb, struct netlink_callback *cb) if (!peers_nest) goto out; ret = 0; - /* If the last cursor was removed via list_del_init in peer_remove, then + lockdep_assert_held(&wg->device_update_lock); + /* If the last cursor was removed in peer_remove or peer_remove_all, then * we just treat this the same as there being no more peers left. The * reason is that seq_nr should indicate to userspace that this isn't a * coherent dump anyway, so they'll try again. */ if (list_empty(&wg->peer_list) || - (ctx->next_peer && list_empty(&ctx->next_peer->peer_list))) { + (ctx->next_peer && ctx->next_peer->is_dead)) { nla_nest_cancel(skb, peers_nest); goto out; } - lockdep_assert_held(&wg->device_update_lock); peer = list_prepare_entry(ctx->next_peer, &wg->peer_list, peer_list); list_for_each_entry_continue(peer, &wg->peer_list, peer_list) { if (get_peer(peer, skb, ctx)) { -- 2.43.0