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KCSAN: data-race in handle_mm_fault / watchdog

Status: auto-closed as invalid on 2020/04/12 06:00
Subsystems: kasan
[Documentation on labels]
First crash: 1639d, last: 1538d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in handle_mm_fault / watchdog

read to 0xffff88812a8ba090 of 8 bytes by task 1061 on cpu 0:
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2b1/0x960 kernel/hung_task.c:289
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff88812a8ba090 of 8 bytes by task 7944 on cpu 1:
 handle_mm_fault+0x4a/0x530 mm/memory.c:4089
 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
 __do_page_fault+0x456/0x8d0 arch/x86/mm/fault.c:1506
 do_page_fault+0x38/0x194 arch/x86/mm/fault.c:1530
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7944 Comm: syz-fuzzer Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 7944 Comm: syz-fuzzer Not tainted 5.5.0-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+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:313
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:416
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_unaligned_write8+0xc7/0x110 kernel/kcsan/core.c:589
 handle_mm_fault+0x4a/0x530 mm/memory.c:4089
 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
 __do_page_fault+0x456/0x8d0 arch/x86/mm/fault.c:1506
 do_page_fault+0x38/0x194 arch/x86/mm/fault.c:1530
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203
RIP: 0033:0x41d490
Code: 01 44 0f b6 0b 49 89 ca 44 89 c1 41 d3 e9 48 83 ff 08 74 0b 41 0f ba e1 04 0f 83 db 00 00 00 41 0f ba e1 00 73 b1 4c 8d 0c 37 <4d> 8b 09 4d 85 c9 74 a5 4c 39 c8 77 a0 49 39 d1 73 9b 4d 89 cb 49
RSP: 002b:00007ffe3709f420 EFLAGS: 00010293
RAX: 000000c420000000 RBX: 000000c41f8e17f3 RCX: 0000000000000000
RDX: 000000c430ee0000 RSI: 000000c42e3d0180 RDI: 0000000000000000
RBP: 00007ffe3709f4b8 R08: 0000000000000000 R09: 000000c42e3d0180
R10: 0000000000000040 R11: 000000c42e3d0180 R12: 0000000000000001
R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000001
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (26):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/02 05:56 https://github.com/google/ktsan.git kcsan 245a43005292 2274ad39 .config console log report ci2-upstream-kcsan-gce
2020/01/25 09:02 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/19 10:27 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2020/01/14 23:18 https://github.com/google/ktsan.git kcsan 245a43005292 fa12bd3c .config console log report ci2-upstream-kcsan-gce
2020/01/14 05:19 https://github.com/google/ktsan.git kcsan 245a43005292 32881205 .config console log report ci2-upstream-kcsan-gce
2020/01/12 14:04 https://github.com/google/ktsan.git kcsan 245a43005292 31290a45 .config console log report ci2-upstream-kcsan-gce
2020/01/09 17:56 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/07 19:34 https://github.com/google/ktsan.git kcsan 245a43005292 1bcd407e .config console log report ci2-upstream-kcsan-gce
2020/01/06 23:55 https://github.com/google/ktsan.git kcsan 245a43005292 53430d97 .config console log report ci2-upstream-kcsan-gce
2020/01/06 13:02 https://github.com/google/ktsan.git kcsan 245a43005292 438e1227 .config console log report ci2-upstream-kcsan-gce
2019/12/31 03:06 https://github.com/google/ktsan.git kcsan 245a43005292 6b36d338 .config console log report ci2-upstream-kcsan-gce
2019/12/04 15:30 https://github.com/google/ktsan.git kcsan ef798c30ba4e b2088328 .config console log report ci2-upstream-kcsan-gce
2019/12/03 12:12 https://github.com/google/ktsan.git kcsan ef798c30ba4e ab342da3 .config console log report ci2-upstream-kcsan-gce
2019/12/02 15:07 https://github.com/google/ktsan.git kcsan ef798c30ba4e f879db37 .config console log report ci2-upstream-kcsan-gce
2019/12/01 07:00 https://github.com/google/ktsan.git kcsan ef798c30ba4e a76bf83f .config console log report ci2-upstream-kcsan-gce
2019/11/18 16:38 https://github.com/google/ktsan.git kcsan 5863cc791e4c d5696d51 .config console log report ci2-upstream-kcsan-gce
2019/11/09 14:30 https://github.com/google/ktsan.git kcsan 94c006602e13 1e35461e .config console log report ci2-upstream-kcsan-gce
2019/11/04 02:38 https://github.com/google/ktsan.git kcsan 05f2236801fe b35fad31 .config console log report ci2-upstream-kcsan-gce
2019/11/03 12:08 https://github.com/google/ktsan.git kcsan 05f2236801fe c9610487 .config console log report ci2-upstream-kcsan-gce
2019/11/03 02:35 https://github.com/google/ktsan.git kcsan 05f2236801fe d603afc9 .config console log report ci2-upstream-kcsan-gce
2019/11/02 03:46 https://github.com/google/ktsan.git kcsan 05f2236801fe 997ccc67 .config console log report ci2-upstream-kcsan-gce
2019/10/30 12:19 https://github.com/google/ktsan.git kcsan 05f2236801fe 5ea87a66 .config console log report ci2-upstream-kcsan-gce
2019/10/28 20:19 https://github.com/google/ktsan.git kcsan 05f2236801fe 439d7b14 .config console log report ci2-upstream-kcsan-gce
2019/10/25 18:55 https://github.com/google/ktsan.git kcsan 05f2236801fe 04ca72cd .config console log report ci2-upstream-kcsan-gce
2019/10/25 00:01 https://github.com/google/ktsan.git kcsan 05f2236801fe d01bb02a .config console log report ci2-upstream-kcsan-gce
2019/10/23 14:45 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.