Message-ID: <000000000000c9559c056a8401a6@google.com>
Date:   Mon, 23 Apr 2018 06:28:01 -0700
From:   syzbot <syzbot+3dfdea57819073a04f21@...kaller.appspotmail.com>
To:     coreteam@...filter.org, davem@...emloft.net, fw@...len.de,
        horms@...ge.net.au, ja@....bg, kadlec@...ckhole.kfki.hu,
        linux-kernel@...r.kernel.org, lvs-devel@...r.kernel.org,
        netdev@...r.kernel.org, netfilter-devel@...r.kernel.org,
        pablo@...filter.org, syzkaller-bugs@...glegroups.com,
        wensong@...ux-vs.org
Subject: KMSAN: uninit-value in ip_vs_lblcr_check_expire

Hello,

syzbot hit the following crash on  
https://github.com/google/kmsan.git/master commit
d2d741e5d1898dfde1a75ea3d29a9a3e2edf0617 (Sun Apr 22 15:05:22 2018 +0000)
kmsan: add initialization for shmem pages
syzbot dashboard link:  
https://syzkaller.appspot.com/bug?extid=3dfdea57819073a04f21

So far this crash happened 2 times on  
https://github.com/google/kmsan.git/master.
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output:  
https://syzkaller.appspot.com/x/log.txt?id=6285034612850688
Kernel config: https://syzkaller.appspot.com/x/.config?id=328654897048964367
compiler: clang version 7.0.0 (trunk 329391)

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3dfdea57819073a04f21@...kaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for  
details.
If you forward the report, please keep this part and the footer.

RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000000004f3 R14: 00000000006fa768 R15: 0000000000000000
==================================================================
BUG: KMSAN: uninit-value in ip_vs_lblcr_check_expire+0x1551/0x1600  
net/netfilter/ipvs/ip_vs_lblcr.c:479
CPU: 0 PID: 13883 Comm: syz-executor4 Not tainted 4.16.0+ #86
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x185/0x1d0 lib/dump_stack.c:53
  kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
  __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
  ip_vs_lblcr_check_expire+0x1551/0x1600 net/netfilter/ipvs/ip_vs_lblcr.c:479
  call_timer_fn+0x26a/0x5a0 kernel/time/timer.c:1326
  expire_timers kernel/time/timer.c:1363 [inline]
  __run_timers+0xda7/0x11c0 kernel/time/timer.c:1666
  run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692
  __do_softirq+0x56d/0x93d kernel/softirq.c:285
  invoke_softirq kernel/softirq.c:365 [inline]
  irq_exit+0x202/0x240 kernel/softirq.c:405
  exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:541
  smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1055
  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
  </IRQ>
RIP: 0010:native_restore_fl arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:78 [inline]
RIP: 0010:dump_stack+0x1af/0x1d0 lib/dump_stack.c:58
RSP: 0018:ffff880156a2ef00 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff12
RAX: ffff8801fddc2590 RBX: ffff88014f62c418 RCX: ffff880000000000
RDX: ffff8801fd9c2590 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff880156a2ef48 R08: 0000000001080000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000cf000109
R13: 0000000000000286 R14: 0000000000000000 R15: 0000000000000000
  fail_dump lib/fault-inject.c:51 [inline]
  should_fail+0x87b/0xab0 lib/fault-inject.c:149
  should_failslab+0x279/0x2a0 mm/failslab.c:32
  slab_pre_alloc_hook mm/slab.h:422 [inline]
  slab_alloc_node mm/slub.c:2663 [inline]
  slab_alloc mm/slub.c:2745 [inline]
  kmem_cache_alloc+0x136/0xb90 mm/slub.c:2750
  dst_alloc+0x295/0x860 net/core/dst.c:104
  __ip6_dst_alloc net/ipv6/route.c:361 [inline]
  ip6_rt_cache_alloc+0x445/0xd00 net/ipv6/route.c:1061
  ip6_pol_route+0x3f19/0x5da0 net/ipv6/route.c:1751
  ip6_pol_route_output+0xe6/0x110 net/ipv6/route.c:1892
  fib6_rule_lookup+0x494/0x720 net/ipv6/fib6_rules.c:87
  ip6_route_output_flags+0x4fa/0x590 net/ipv6/route.c:1920
  ip6_dst_lookup_tail+0x2fe/0x1a60 net/ipv6/ip6_output.c:992
  ip6_dst_lookup_flow+0xfc/0x270 net/ipv6/ip6_output.c:1093
  rawv6_sendmsg+0x1b05/0x4fb0 net/ipv6/raw.c:908
  inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg net/socket.c:640 [inline]
  ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
  __sys_sendmsg net/socket.c:2080 [inline]
  SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
  SyS_sendmsg+0x54/0x80 net/socket.c:2087
  do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455389
RSP: 002b:00007fa5b1000c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa5b10016d4 RCX: 0000000000455389
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000000004f3 R14: 00000000006fa768 R15: 0000000000000000

Uninit was created at:
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
  kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:814
  kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:868
  __alloc_pages_nodemask+0xf5b/0x5dc0 mm/page_alloc.c:4283
  alloc_pages_current+0x6b5/0x970 mm/mempolicy.c:2055
  alloc_pages include/linux/gfp.h:494 [inline]
  kmalloc_order mm/slab_common.c:1164 [inline]
  kmalloc_order_trace+0xb9/0x390 mm/slab_common.c:1175
  kmalloc_large include/linux/slab.h:446 [inline]
  __kmalloc+0x332/0x350 mm/slub.c:3778
  kmalloc include/linux/slab.h:517 [inline]
  ip_vs_lblcr_init_svc+0x57/0x310 net/netfilter/ipvs/ip_vs_lblcr.c:518
  ip_vs_bind_scheduler+0xa4/0x1e0 net/netfilter/ipvs/ip_vs_sched.c:51
  ip_vs_add_service+0xa91/0x1d70 net/netfilter/ipvs/ip_vs_ctl.c:1265
  do_ip_vs_set_ctl+0x25c8/0x2790 net/netfilter/ipvs/ip_vs_ctl.c:2457
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x476/0x4d0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x24b/0x2b0 net/ipv4/ip_sockglue.c:1261
  dccp_setsockopt+0x1c3/0x1f0 net/dccp/proto.c:576
  sock_common_setsockopt+0x136/0x170 net/core/sock.c:2975
  SYSC_setsockopt+0x4b8/0x570 net/socket.c:1849
  SyS_setsockopt+0x76/0xa0 net/socket.c:1828
  do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
==================================================================


---
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