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 000EF3195EF; Thu, 16 Jul 2026 14:04:54 +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=1784210696; cv=none; b=qECWhZtScB4t9auq9kU9o+MTgFsONvhCkSK2ElSsQHnNkhRaujJ27mhxm9qxCu9bAmCTxTYQ3cwNiJcHwIpfE/On+RzwsDa4sMfLubuUBkKsrgpkBREBsNkpc+vM5U7vY0DGWZjYll3iKUSpvkhScn40pV6UkMHmROfqEH6U+RE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784210696; c=relaxed/simple; bh=Fjh0eAXQiZGCv9bLNPFE8VdD3cPRCBnMpUybtH6PSRE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jpVUHqo4T3oNfYkSG5f7QrFXeiNiMU1RSCiAgJqrkTerw9BomsWcmKojCvhqPnf0owkwwLmv9lXNDzJSgVAPaFfaHPwD73sy5iXsxvCw6aL5VP4Rcrhwt3H58Le6Rv/SySkiGzoaWOBISC7+79q3bVRjOqw+30AKxydfpe2VsfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=q0/x/kvR; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="q0/x/kvR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 666B21F000E9; Thu, 16 Jul 2026 14:04:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784210694; bh=XUYNzcmvGdfhMcto98E8RNPwbJR1AnIUPYYhj5FjCfM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=q0/x/kvR4IWJmSdMCsoZX5O1mSKooIEpdAVJdNBh4Yt4sI4+N77sYRu8tqpqoBWZN OIcehKPaZiBkKTIpZ+ddN41l3p0L9uhsq9f/DwkvMmB3EAf/ZlXQEdZufNtDmNdRSo 3mZKRAZMuRsDTVQgwhRcO1xE4E1NXZErIWGcUvKc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Weiming Shi , Xiang Mei , Jozsef Kadlecsik , Florian Westphal Subject: [PATCH 6.18 146/480] netfilter: ipset: fix race between dump and ip_set_list resize Date: Thu, 16 Jul 2026 15:28:13 +0200 Message-ID: <20260716133047.868870511@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133044.672218725@linuxfoundation.org> References: <20260716133044.672218725@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiang Mei commit 7cd9103283b26b917360ec99d7d2f2d761bcf1ab upstream. The release path of ip_set_dump_do() and ip_set_dump_done() read inst->ip_set_list via ip_set_ref_netlink(), a plain rcu_dereference_raw() of the array pointer. These run from netlink_recvmsg() without the nfnl mutex and without an RCU read-side critical section. A concurrent ip_set_create() can grow the array: it publishes the new array, calls synchronize_net() and then kvfree()s the old one. Since the dump paths read the array outside any RCU reader, synchronize_net() does not wait for them and the old array can be freed while they still index into it, causing a use-after-free. The dumped set itself stays pinned via set->ref_netlink, so only the array load needs protecting. Take rcu_read_lock() around it, matching ip_set_get_byname() and __ip_set_put_byindex(). BUG: KASAN: slab-use-after-free in ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697) Read of size 8 at addr ffff88800b5c4018 by task exploit/150 Call Trace: ... kasan_report (mm/kasan/report.c:595) ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697) netlink_dump (net/netlink/af_netlink.c:2325) netlink_recvmsg (net/netlink/af_netlink.c:1976) sock_recvmsg (net/socket.c:1159) __sys_recvfrom (net/socket.c:2315) ... Oops: general protection fault, probably for non-canonical address ... KASAN NOPTI KASAN: maybe wild-memory-access in range [0x02d6...d0-0x02d6...d7] RIP: 0010:ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1698) Kernel panic - not syncing: Fatal exception Fixes: 8a02bdd50b2e ("netfilter: ipset: Fix calling ip_set() macro at dumping") Cc: stable@vger.kernel.org Reported-by: Weiming Shi Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Xiang Mei Acked-by: Jozsef Kadlecsik Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman --- net/netfilter/ipset/ip_set_core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1480,7 +1480,11 @@ ip_set_dump_done(struct netlink_callback struct ip_set_net *inst = (struct ip_set_net *)cb->args[IPSET_CB_NET]; ip_set_id_t index = (ip_set_id_t)cb->args[IPSET_CB_INDEX]; - struct ip_set *set = ip_set_ref_netlink(inst, index); + struct ip_set *set; + + rcu_read_lock(); + set = ip_set_ref_netlink(inst, index); + rcu_read_unlock(); if (set->variant->uref) set->variant->uref(set, cb, false); @@ -1685,7 +1689,9 @@ next_set: release_refcount: /* If there was an error or set is done, release set */ if (ret || !cb->args[IPSET_CB_ARG0]) { + rcu_read_lock(); set = ip_set_ref_netlink(inst, index); + rcu_read_unlock(); if (set->variant->uref) set->variant->uref(set, cb, false); pr_debug("release set %s\n", set->name);