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[209.132.180.67]) by mx.google.com with ESMTP id w16si6707707pll.113.2019.03.22.04.25.57; Fri, 22 Mar 2019 04:26:12 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=BjLoiRRr; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729139AbfCVLYe (ORCPT + 99 others); Fri, 22 Mar 2019 07:24:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:51590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729132AbfCVLYb (ORCPT ); Fri, 22 Mar 2019 07:24:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7DD6121917; Fri, 22 Mar 2019 11:24:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553253871; bh=oVCrpmQzNLeFeZc5+o6nchcAWe8zlLHLbIpeRiuOOhQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BjLoiRRrcHJBtj5SzXycLbW12b5INQtrhiKbDCQYfUSMetFng7QIft1GZt1k8d/Ut U460OxGIsdB2JClkBC5Z2xU0z7wGyE7E8rpYGqxoQ1QSU9L+IfP0igTJyjXO1GAlMW 0YJtbv8Bnnwrt1nmbfxQ47zZ+HC1RxNwuT2sXk6c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot+04babcefcd396fabec37@syzkaller.appspotmail.com, andrew hendry , "David S. Miller" Subject: [PATCH 3.18 082/134] net/x25: fix use-after-free in x25_device_event() Date: Fri, 22 Mar 2019 12:14:55 +0100 Message-Id: <20190322111216.048533799@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111210.465931067@linuxfoundation.org> References: <20190322111210.465931067@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 95d6ebd53c79522bf9502dbc7e89e0d63f94dae4 ] In case of failure x25_connect() does a x25_neigh_put(x25->neighbour) but forgets to clear x25->neighbour pointer, thus triggering use-after-free. Since the socket is visible in x25_list, we need to hold x25_list_lock to protect the operation. syzbot report : BUG: KASAN: use-after-free in x25_kill_by_device net/x25/af_x25.c:217 [inline] BUG: KASAN: use-after-free in x25_device_event+0x296/0x2b0 net/x25/af_x25.c:252 Read of size 8 at addr ffff8880a030edd0 by task syz-executor003/7854 CPU: 0 PID: 7854 Comm: syz-executor003 Not tainted 5.0.0+ #97 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 x25_kill_by_device net/x25/af_x25.c:217 [inline] x25_device_event+0x296/0x2b0 net/x25/af_x25.c:252 notifier_call_chain+0xc7/0x240 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1739 call_netdevice_notifiers_extack net/core/dev.c:1751 [inline] call_netdevice_notifiers net/core/dev.c:1765 [inline] __dev_notify_flags+0x1e9/0x2c0 net/core/dev.c:7607 dev_change_flags+0x10d/0x170 net/core/dev.c:7643 dev_ifsioc+0x2b0/0x940 net/core/dev_ioctl.c:237 dev_ioctl+0x1b8/0xc70 net/core/dev_ioctl.c:488 sock_do_ioctl+0x1bd/0x300 net/socket.c:995 sock_ioctl+0x32b/0x610 net/socket.c:1096 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4467c9 Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdbea222d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006dbc58 RCX: 00000000004467c9 RDX: 0000000020000340 RSI: 0000000000008914 RDI: 0000000000000003 RBP: 00000000006dbc50 R08: 00007fdbea223700 R09: 0000000000000000 R10: 00007fdbea223700 R11: 0000000000000246 R12: 00000000006dbc5c R13: 6000030030626669 R14: 0000000000000000 R15: 0000000030626669 Allocated by task 7843: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:509 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3615 kmalloc include/linux/slab.h:545 [inline] x25_link_device_up+0x46/0x3f0 net/x25/x25_link.c:249 x25_device_event+0x116/0x2b0 net/x25/af_x25.c:242 notifier_call_chain+0xc7/0x240 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1739 call_netdevice_notifiers_extack net/core/dev.c:1751 [inline] call_netdevice_notifiers net/core/dev.c:1765 [inline] __dev_notify_flags+0x121/0x2c0 net/core/dev.c:7605 dev_change_flags+0x10d/0x170 net/core/dev.c:7643 dev_ifsioc+0x2b0/0x940 net/core/dev_ioctl.c:237 dev_ioctl+0x1b8/0xc70 net/core/dev_ioctl.c:488 sock_do_ioctl+0x1bd/0x300 net/socket.c:995 sock_ioctl+0x32b/0x610 net/socket.c:1096 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7865: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3494 [inline] kfree+0xcf/0x230 mm/slab.c:3811 x25_neigh_put include/net/x25.h:253 [inline] x25_connect+0x8d8/0xde0 net/x25/af_x25.c:824 __sys_connect+0x266/0x330 net/socket.c:1685 __do_sys_connect net/socket.c:1696 [inline] __se_sys_connect net/socket.c:1693 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1693 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a030edc0 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 16 bytes inside of 256-byte region [ffff8880a030edc0, ffff8880a030eec0) The buggy address belongs to the page: page:ffffea000280c380 count:1 mapcount:0 mapping:ffff88812c3f07c0 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002806788 ffffea00027f0188 ffff88812c3f07c0 raw: 0000000000000000 ffff8880a030e000 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Signed-off-by: Eric Dumazet Reported-by: syzbot+04babcefcd396fabec37@syzkaller.appspotmail.com Cc: andrew hendry Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/x25/af_x25.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -812,8 +812,12 @@ static int x25_connect(struct socket *so sock->state = SS_CONNECTED; rc = 0; out_put_neigh: - if (rc) + if (rc) { + read_lock_bh(&x25_list_lock); x25_neigh_put(x25->neighbour); + x25->neighbour = NULL; + read_unlock_bh(&x25_list_lock); + } out_put_route: x25_route_put(rt); out: