From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20D04C2BA83 for ; Fri, 14 Feb 2020 18:09:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D67BE2187F for ; Fri, 14 Feb 2020 18:09:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Pkp9V0Gj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731392AbgBNPyC (ORCPT ); Fri, 14 Feb 2020 10:54:02 -0500 Received: from mail-pl1-f201.google.com ([209.85.214.201]:33057 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731377AbgBNPyB (ORCPT ); Fri, 14 Feb 2020 10:54:01 -0500 Received: by mail-pl1-f201.google.com with SMTP id bd7so5430775plb.0 for ; Fri, 14 Feb 2020 07:53:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=IIt27wT5sPWzKch1gTPWYRaZBvc/KKCKHQt7WmhoH40=; b=Pkp9V0Gj8RiarpOzw1dhuV5VjoCwwWTBoZiSKO6qP33Qkdm2i0kTIIqpc3J7/h6Vn1 /OZ42xfWeXNCmeRK/Lj7VJ0EZmfxeTSTVHsRGlk1CH/xot8n8sIJO0WFSE1oS+qGaeIe UfLrE1po02scOhoKFO6pXRbuHiox5X0WB/UZLoFGf4iDyQEN6TNNAL9Botp9SlYgWxoi aLkxmiLyMiBhIF2AUQkqKoqDo5CVYo2T2Gt2RF3ZS2AkfnBhZCUgs12hXD+fKJunPp/N WXIVExrT80/zGfnZnol4X2gaRZiwwDjpu9hID/NmBmUPQ5dFzKsDd3GUZePVn6A19qeS orFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=IIt27wT5sPWzKch1gTPWYRaZBvc/KKCKHQt7WmhoH40=; b=JFImFEdd6vb3maEJONCrBsrPRktQRjb2catu5tNgdU5XZuDjUebSlBDg5LA7kh5RjO kSV9JWBzX9axlPIA1ZGKOxfOCCYyXXgq92Tzg42RiaZEHqHL40BrI+VfxipuK9yN2SpE 9ILSVFiCTuZa++j8xfUVAY32PO2dzaXCsjPXKGoPkFI5xpMWi5GaUeBxnlFwZg6/FCVf Z8sPeUWldYEzkwryFLevOz87Cg/DkM6tvUZoC8EA945nI85HPTrxPz6/bTT/3trkT/gA 7iJlmArDDsK5NhIX1NDj4zJwejFYwufxM6xRt0Rmbtld6JSxbx+kBXcrrl213qy/UUfT pGmw== X-Gm-Message-State: APjAAAW8gzlWxEUnvj/ybEGVXM95quSH94TFrbbpDqbW3hBq9OG9GN1Z +t1WHh0FctiAwYrB35XmxQBXgd4ar84lFQ== X-Google-Smtp-Source: APXvYqwrjqD/V5Tf03LHMosp6p1iYWWVqrMtY9JWrSAeseFvUlXr2tgwrg6rD0qIneDWjUplKOdz5rDpSMNHQQ== X-Received: by 2002:a65:420b:: with SMTP id c11mr4023054pgq.297.1581695639002; Fri, 14 Feb 2020 07:53:59 -0800 (PST) Date: Fri, 14 Feb 2020 07:53:53 -0800 Message-Id: <20200214155353.71062-1-edumazet@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog Subject: [PATCH net] net: add strict checks in netdev_name_node_alt_destroy() From: Eric Dumazet To: "David S . Miller" Cc: netdev , Eric Dumazet , Eric Dumazet , syzbot , Jiri Pirko Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org netdev_name_node_alt_destroy() does a lookup over all device names of a namespace. We need to make sure the name belongs to the device of interest, and that we do not destroy its primary name, since we rely on it being not deleted : dev->name_node would indeed point to freed memory. syzbot report was the following : BUG: KASAN: use-after-free in dev_net include/linux/netdevice.h:2206 [inline] BUG: KASAN: use-after-free in mld_force_mld_version net/ipv6/mcast.c:1172 [inline] BUG: KASAN: use-after-free in mld_in_v2_mode_only net/ipv6/mcast.c:1180 [inline] BUG: KASAN: use-after-free in mld_in_v1_mode+0x203/0x230 net/ipv6/mcast.c:1190 Read of size 8 at addr ffff88809886c588 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 dev_net include/linux/netdevice.h:2206 [inline] mld_force_mld_version net/ipv6/mcast.c:1172 [inline] mld_in_v2_mode_only net/ipv6/mcast.c:1180 [inline] mld_in_v1_mode+0x203/0x230 net/ipv6/mcast.c:1190 mld_send_initial_cr net/ipv6/mcast.c:2083 [inline] mld_dad_timer_expire+0x24/0x230 net/ipv6/mcast.c:2118 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1146 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 68 73 c5 f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 94 be 59 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 84 be 59 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 de 2a 74 f9 e8 09 RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff136761a RBX: ffff8880a99fc340 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a99fcbd4 RBP: ffffc90000d3fd98 R08: ffff8880a99fc340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff8aa5a1c0 R14: 0000000000000000 R15: 0000000000000001 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:686 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 start_secondary+0x2f4/0x410 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 Allocated by task 10229: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x68/0x100 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] kvzalloc include/linux/mm.h:653 [inline] alloc_netdev_mqs+0x98/0xe40 net/core/dev.c:9797 rtnl_create_link+0x22d/0xaf0 net/core/rtnetlink.c:3047 __rtnl_newlink+0xf9f/0x1790 net/core/rtnetlink.c:3309 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3377 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 __sys_sendto+0x262/0x380 net/socket.c:1998 __do_compat_sys_socketcall net/compat.c:771 [inline] __se_compat_sys_socketcall net/compat.c:719 [inline] __ia32_compat_sys_socketcall+0x530/0x710 net/compat.c:719 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 10229: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 __netdev_name_node_alt_destroy+0x1ff/0x2a0 net/core/dev.c:322 netdev_name_node_alt_destroy+0x57/0x80 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop.isra.0+0x575/0x6f0 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x46/0x60 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __compat_sys_sendmsg net/compat.c:642 [inline] __do_compat_sys_sendmsg net/compat.c:649 [inline] __se_compat_sys_sendmsg net/compat.c:646 [inline] __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:646 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 The buggy address belongs to the object at ffff88809886c000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1416 bytes inside of 4096-byte region [ffff88809886c000, ffff88809886d000) The buggy address belongs to the page: page:ffffea0002621b00 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002610d08 ffffea0002607608 ffff8880aa402000 raw: 0000000000000000 ffff88809886c000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809886c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809886c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809886c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809886c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809886c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Jiri Pirko --- net/core/dev.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index a6316b336128cdb31eea6e80f1a47620abbd0d31..b6d13f3f1e5ab4f906f4bc9611e4cb37a55f3396 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -331,6 +331,12 @@ int netdev_name_node_alt_destroy(struct net_device *dev, const char *name) name_node = netdev_name_node_lookup(net, name); if (!name_node) return -ENOENT; + /* lookup might have found our primary name or a name belonging + * to another device. + */ + if (name_node == dev->name_node || name_node->dev != dev) + return -EINVAL; + __netdev_name_node_alt_destroy(name_node); return 0; -- 2.25.0.265.gbab2e86ba0-goog