Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 835FEC433EF for ; Mon, 13 Dec 2021 10:06:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235915AbhLMKGf (ORCPT ); Mon, 13 Dec 2021 05:06:35 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:47520 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238789AbhLMKBg (ORCPT ); Mon, 13 Dec 2021 05:01:36 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E0B29B80EAE; Mon, 13 Dec 2021 10:01:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E993C34602; Mon, 13 Dec 2021 10:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1639389693; bh=B02hXA2HNaN8oaPxgTWxPqBUd8PS/ZcUF6Be2GpFiXM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1Wb9uwkHCGJ0GYXyVa3K2Dq5SeyVo6MRC+AsEvf1zT+WohEZEhV4eT0G2+7650f4i xh744qQ1MAnf42z0JSq/NqMAIsga8ixRlF5cvJkDVGbcsjFKXwHswZTPM+8iqlfC6x d6QwJnCPowifFxRTA3BQ2hrstrFazDDgwWdFxFZM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Roopa Prabhu , David Ahern , Jakub Kicinski Subject: [PATCH 5.15 133/171] net, neigh: clear whole pneigh_entry at alloc time Date: Mon, 13 Dec 2021 10:30:48 +0100 Message-Id: <20211213092949.523659853@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211213092945.091487407@linuxfoundation.org> References: <20211213092945.091487407@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet commit e195e9b5dee6459d8c8e6a314cc71a644a0537fd upstream. Commit 2c611ad97a82 ("net, neigh: Extend neigh->flags to 32 bit to allow for extensions") enables a new KMSAM warning [1] I think the bug is actually older, because the following intruction only occurred if ndm->ndm_flags had NTF_PROXY set. pn->flags = ndm->ndm_flags; Let's clear all pneigh_entry fields at alloc time. [1] BUG: KMSAN: uninit-value in pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593 pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593 pneigh_dump_table net/core/neighbour.c:2715 [inline] neigh_dump_info+0x1e3f/0x2c60 net/core/neighbour.c:2832 netlink_dump+0xaca/0x16a0 net/netlink/af_netlink.c:2265 __netlink_dump_start+0xd1c/0xee0 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:254 [inline] rtnetlink_rcv_msg+0x181b/0x18c0 net/core/rtnetlink.c:5534 netlink_rcv_skb+0x447/0x800 net/netlink/af_netlink.c:2491 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5589 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x1095/0x1360 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x16f3/0x1870 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_write_iter+0x594/0x690 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x1318/0x2030 fs/read_write.c:590 ksys_write+0x28c/0x520 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:3251 [inline] slab_alloc mm/slub.c:3259 [inline] __kmalloc+0xc3c/0x12d0 mm/slub.c:4437 kmalloc include/linux/slab.h:595 [inline] pneigh_lookup+0x60f/0xd70 net/core/neighbour.c:766 arp_req_set_public net/ipv4/arp.c:1016 [inline] arp_req_set+0x430/0x10a0 net/ipv4/arp.c:1032 arp_ioctl+0x8d4/0xb60 net/ipv4/arp.c:1232 inet_ioctl+0x4ef/0x820 net/ipv4/af_inet.c:947 sock_do_ioctl net/socket.c:1118 [inline] sock_ioctl+0xa3f/0x13e0 net/socket.c:1235 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0x2df/0x4a0 fs/ioctl.c:860 __x64_sys_ioctl+0xd8/0x110 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae CPU: 1 PID: 20001 Comm: syz-executor.0 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 62dd93181aaa ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.") Signed-off-by: Eric Dumazet Cc: Roopa Prabhu Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20211206165329.1049835-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/core/neighbour.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -733,11 +733,10 @@ struct pneigh_entry * pneigh_lookup(stru ASSERT_RTNL(); - n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL); + n = kzalloc(sizeof(*n) + key_len, GFP_KERNEL); if (!n) goto out; - n->protocol = 0; write_pnet(&n->net, net); memcpy(n->key, pkey, key_len); n->dev = dev;