syzbot


KCSAN: data-race in schedule_hrtimeout_range_clock / watchdog

Status: closed as invalid on 2019/11/19 13:44
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1028d, last: 1028d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in schedule_hrtimeout_range_clock / watchdog (2) 9 814d 978d 0/23 closed as invalid on 2020/06/18 14:24

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

read to 0xffff88812a8ec010 of 8 bytes by task 1061 on cpu 0:
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2c3/0x7c0 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 0xffff88812a8ec010 of 8 bytes by task 7177 on cpu 1:
 schedule_hrtimeout_range_clock+0x14e/0x1e0 kernel/time/hrtimer.c:2132
 schedule_hrtimeout_range+0x34/0x50 kernel/time/hrtimer.c:2172
 poll_schedule_timeout.constprop.0+0x75/0xc0 fs/select.c:243
 do_select+0xd7f/0x1020 fs/select.c:603
 core_sys_select+0x381/0x550 fs/select.c:677
 do_pselect.constprop.0+0x11d/0x160 fs/select.c:759
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6 fs/select.c:769 [inline]
 __x64_sys_pselect6+0x12e/0x170 fs/select.c:769
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7177 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #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: 7177 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302
 __kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411
 __tsan_write8 kernel/kcsan/kcsan.c:36 [inline]
 __tsan_write8+0x32/0x40 kernel/kcsan/kcsan.c:36
 schedule_hrtimeout_range_clock+0x14e/0x1e0 kernel/time/hrtimer.c:2132
 schedule_hrtimeout_range+0x34/0x50 kernel/time/hrtimer.c:2172
 poll_schedule_timeout.constprop.0+0x75/0xc0 fs/select.c:243
 do_select+0xd7f/0x1020 fs/select.c:603
 core_sys_select+0x381/0x550 fs/select.c:677
 do_pselect.constprop.0+0x11d/0x160 fs/select.c:759
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6 fs/select.c:769 [inline]
 __x64_sys_pselect6+0x12e/0x170 fs/select.c:769
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ac23
Code: 48 89 44 24 08 bf 00 00 00 00 be 00 00 00 00 ba 00 00 00 00 41 ba 00 00 00 00 49 89 e0 41 b9 00 00 00 00 b8 0e 01 00 00 0f 05 <48> 8b 6c 24 10 48 83 c4 18 c3 cc cc cc b8 ba 00 00 00 0f 05 89 44
RSP: 002b:000000c4202cfe38 EFLAGS: 00000206 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045ac23
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000c4202cfe48 R08: 000000c4202cfe38 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000000c420904000
R13: 00000000000000da R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2019/10/25 23:45 https://github.com/google/ktsan.git kcsan 05f2236801fe 413926c5 .config log report