Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753505AbdCAW0r (ORCPT ); Wed, 1 Mar 2017 17:26:47 -0500 Received: from mail-ua0-f172.google.com ([209.85.217.172]:33193 "EHLO mail-ua0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbdCAWZ6 (ORCPT ); Wed, 1 Mar 2017 17:25:58 -0500 MIME-Version: 1.0 From: Dmitry Vyukov Date: Wed, 1 Mar 2017 20:27:25 +0100 Message-ID: Subject: net: use-after-free in neigh_timer_handler/sock_wfree To: David Miller , netdev , LKML , Cong Wang , Eric Dumazet Cc: syzkaller , Alexey Kuznetsov , James Morris Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4014 Lines: 89 Hello, I am seeing the following use-after-free report while running syzkaller fuzzer on linux-next/3e7350242c6f3d41d28e03418bd781cc1b7bad5f: ================================================================== BUG: KASAN: use-after-free in constant_test_bit arch/x86/include/asm/bitops.h:324 [inline] at addr ffff8801c56d5460 BUG: KASAN: use-after-free in sock_flag include/net/sock.h:789 [inline] at addr ffff8801c56d5460 BUG: KASAN: use-after-free in sock_wfree+0x118/0x120 net/core/sock.c:1630 at addr ffff8801c56d5460 Read of size 8 by task syz-fuzzer/3261 CPU: 0 PID: 3261 Comm: syz-fuzzer Not tainted 4.10.0-next-20170224+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:332 constant_test_bit arch/x86/include/asm/bitops.h:324 [inline] sock_flag include/net/sock.h:789 [inline] sock_wfree+0x118/0x120 net/core/sock.c:1630 skb_release_head_state+0xfc/0x200 net/core/skbuff.c:654 skb_release_all+0x15/0x60 net/core/skbuff.c:667 __kfree_skb+0x15/0x20 net/core/skbuff.c:683 kfree_skb+0x16e/0x4c0 net/core/skbuff.c:704 ndisc_error_report+0xbb/0x190 net/ipv6/ndisc.c:683 neigh_invalidate+0x23e/0x570 net/core/neighbour.c:848 neigh_timer_handler+0x4e7/0x1140 net/core/neighbour.c:933 call_timer_fn+0x241/0x820 kernel/time/timer.c:1266 expire_timers kernel/time/timer.c:1305 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1599 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1612 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:658 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 RIP: 0033:0x46a7c3 RSP: 002b:000000c83e2d5180 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000000 RBX: 000000000046a7b0 RCX: 000000c820471200 RDX: 0000000000000020 RSI: 000000c839e1bba0 RDI: 000000c83e2d5190 RBP: 0000000000000002 R08: 0000000000000002 R09: 0000000000000073 R10: 000000c839a31b03 R11: 000000c839e1bbf8 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000010 R15: 0000000001263e90 Object at ffff8801c56d5400, in cache RAWv6 size: 1480 Allocated: PID = 12540 kmem_cache_alloc+0x102/0x680 mm/slab.c:3568 sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1332 sk_alloc+0x8c/0x470 net/core/sock.c:1394 inet6_create+0x44d/0x1140 net/ipv6/af_inet6.c:183 __sock_create+0x4e4/0x870 net/socket.c:1197 sock_create net/socket.c:1237 [inline] SYSC_socket net/socket.c:1267 [inline] SyS_socket+0xf9/0x230 net/socket.c:1247 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed: PID = 12572 kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:580 __cache_free mm/slab.c:3510 [inline] kmem_cache_free+0x71/0x240 mm/slab.c:3770 sk_prot_free net/core/sock.c:1375 [inline] __sk_destruct+0x487/0x6b0 net/core/sock.c:1450 sk_destruct+0x47/0x80 net/core/sock.c:1458 __sk_free+0x57/0x230 net/core/sock.c:1466 sk_free+0x23/0x30 net/core/sock.c:1477 sock_put include/net/sock.h:1644 [inline] sk_common_release+0x3bf/0x5e0 net/core/sock.c:2781 rawv6_close+0x4c/0x80 net/ipv6/raw.c:1218 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1061 __fput+0x332/0x7f0 fs/file_table.c:208 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x18a/0x260 kernel/task_work.c:116 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0x1956/0x2900 kernel/exit.c:873 do_group_exit+0x149/0x420 kernel/exit.c:977 get_signal+0x7e0/0x1820 kernel/signal.c:2313 do_signal+0xd2/0x2190 arch/x86/kernel/signal.c:807 exit_to_usermode_loop+0x200/0x2a0 arch/x86/entry/common.c:156 prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline] syscall_return_slowpath+0x4d3/0x570 arch/x86/entry/common.c:259 entry_SYSCALL_64_fastpath+0xc0/0xc2