Re: KASAN: stack-out-of-bounds Read in account_system_index_time

[Dmitry Vyukov]

On Mon, Jul 9, 2018 at 5:09 AM, syzbot
<syzbot+df1a417b3485bed2c190@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    ca04b3cca11a Merge tag 'armsoc-fixes' of git://git.kernel...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=11f1e968400000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2ca6c7a31d407f86
> dashboard link: https://syzkaller.appspot.com/bug?extid=df1a417b3485bed2c190
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=17f8f6d0400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15e88a78400000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+df1a417b3485bed2c190@xxxxxxxxxxxxxxxxxxxxxxxxx

#syz fix: bpf: sockhash, disallow bpf_tcp_close and update in parallel

> ==================================================================
> BUG: KASAN: stack-out-of-bounds in __read_once_size
> include/linux/compiler.h:188 [inline]
> BUG: KASAN: stack-out-of-bounds in get_running_cputimer
> include/linux/sched/cputime.h:85 [inline]
> BUG: KASAN: stack-out-of-bounds in account_group_system_time
> include/linux/sched/cputime.h:149 [inline]
> BUG: KASAN: stack-out-of-bounds in account_system_index_time+0x512/0x5c0
> kernel/sched/cputime.c:168
> Read of size 1 at addr ffff8801afffc278 by task syz-executor708/17155
>
> CPU: 1 PID: 17155 Comm: syz-executor708 Not tainted 4.18.0-rc3+ #137
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>  <IRQ>
>  __dump_stack lib/dump_stack.c:77 [inline]
>  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
>  print_address_description+0x6c/0x20b mm/kasan/report.c:256
>  kasan_report_error mm/kasan/report.c:354 [inline]
>  kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
>  __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
>  __read_once_size include/linux/compiler.h:188 [inline]
>  get_running_cputimer include/linux/sched/cputime.h:85 [inline]
>  account_group_system_time include/linux/sched/cputime.h:149 [inline]
>  account_system_index_time+0x512/0x5c0 kernel/sched/cputime.c:168
>  account_system_time+0x7f/0xb0 kernel/sched/cputime.c:199
>  account_process_tick+0x76/0x240 kernel/sched/cputime.c:498
>  update_process_times+0x21/0x70 kernel/time/timer.c:1634
>  tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
>  tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
>  __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
>  __hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
>  hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
>  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
>  smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050
>  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
>  </IRQ>
>
> Allocated by task 905967825:
> BUG: unable to handle kernel paging request at ffffffff8c42a180
> PGD 8e6d067 P4D 8e6d067 PUD 8e6e063 PMD 0
> Thread overran stack, or stack corrupted
> Oops: 0000 [#1] SMP KASAN
> CPU: 1 PID: 17155 Comm: syz-executor708 Not tainted 4.18.0-rc3+ #137
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:depot_fetch_stack+0x10/0x30 lib/stackdepot.c:201
> Code: e8 65 1b 47 fe e9 b3 fd ff ff e8 5b 1b 47 fe e9 55 fd ff ff 90 90 90
> 90 90 90 89 f8 c1 ef 11 25 ff ff 1f 00 81 e7 f0 3f 00 00 <48> 03 3c c5 80 19
> 43 8b 8b 47 0c 48 83 c7 18 c7 46 10 00 00 00 00
> RSP: 0018:ffff8801daf078b8 EFLAGS: 00010006
> RAX: 00000000001ff100 RBX: ffff8801afffc654 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffff8801daf078c0 RDI: 0000000000000ff0
> RBP: ffff8801daf078e8 R08: ffff8801adacc6c0 R09: ffffed003b5e3ec2
> R10: ffffed003b5e3ec2 R11: ffff8801daf1f617 R12: ffff8801afffc140
> R13: ffff8801afffc278 R14: ffff8801da97be40 R15: ffff8801afffc650
> FS:  0000000000c14940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffff8c42a180 CR3: 00000001ae362000 CR4: 00000000001406e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <IRQ>
>  describe_object mm/kasan/report.c:243 [inline]
>  print_address_description+0xfb/0x20b mm/kasan/report.c:263
>  kasan_report_error mm/kasan/report.c:354 [inline]
>  kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
>  __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
>  __read_once_size include/linux/compiler.h:188 [inline]
>  get_running_cputimer include/linux/sched/cputime.h:85 [inline]
>  account_group_system_time include/linux/sched/cputime.h:149 [inline]
>  account_system_index_time+0x512/0x5c0 kernel/sched/cputime.c:168
>  account_system_time+0x7f/0xb0 kernel/sched/cputime.c:199
>  account_process_tick+0x76/0x240 kernel/sched/cputime.c:498
>  update_process_times+0x21/0x70 kernel/time/timer.c:1634
>  tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
>  tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
>  __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
>  __hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
>  hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
>  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
>  smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050
>  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
>  </IRQ>
> Modules linked in:
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> CR2: ffffffff8c42a180
> ---[ end trace 9194b6f505fa64d0 ]---
> RIP: 0010:depot_fetch_stack+0x10/0x30 lib/stackdepot.c:201
> Code: e8 65 1b 47 fe e9 b3 fd ff ff e8 5b 1b 47 fe e9 55 fd ff ff 90 90 90
> 90 90 90 89 f8 c1 ef 11 25 ff ff 1f 00 81 e7 f0 3f 00 00 <48> 03 3c c5 80 19
> 43 8b 8b 47 0c 48 83 c7 18 c7 46 10 00 00 00 00
> RSP: 0018:ffff8801daf078b8 EFLAGS: 00010006
> RAX: 00000000001ff100 RBX: ffff8801afffc654 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffff8801daf078c0 RDI: 0000000000000ff0
> RBP: ffff8801daf078e8 R08: ffff8801adacc6c0 R09: ffffed003b5e3ec2
> R10: ffffed003b5e3ec2 R11: ffff8801daf1f617 R12: ffff8801afffc140
> R13: ffff8801afffc278 R14: ffff8801da97be40 R15: ffff8801afffc650
> FS:  0000000000c14940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffff8c42a180 CR3: 00000001ae362000 CR4: 00000000001406e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
>
> ---
> This bug is generated by a bot. It may contain errors.
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>
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>
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