syzbot


KMSAN: uninit-value in schedule_timeout

Status: closed as invalid on 2018/09/05 11:10
Subsystems: kernel
[Documentation on labels]
First crash: 2621d, last: 2621d

Sample crash report:
==================================================================
BUG: KMSAN: uninit-value in schedule_timeout+0x526/0x580 kernel/time/timer.c:1810
CPU: 1 PID: 9 Comm: rcu_sched Not tainted 4.17.0+ #9
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
 schedule_timeout+0x526/0x580 kernel/time/timer.c:1810
 rcu_gp_kthread+0x21e1/0x38d0 kernel/rcu/tree.c:2231
 kthread+0x4db/0x6c0 kernel/kthread.c:241
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:413

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:297 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:689
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464
 do_timer+0xa0/0xc0 kernel/time/timekeeping.c:2177
 tick_do_update_jiffies64+0x28a/0x4b0 kernel/time/tick-sched.c:88
 tick_sched_do_timer kernel/time/tick-sched.c:135 [inline]
 tick_sched_timer+0xf8/0x520 kernel/time/tick-sched.c:1267
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0xc54/0x1630 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x451/0x13c0 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt+0x6b/0x250 arch/x86/kernel/apic/apic.c:1025
 smp_apic_timer_interrupt+0x5a/0x90 arch/x86/kernel/apic/apic.c:1053

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:297 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:689
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464
 do_timer+0xa0/0xc0 kernel/time/timekeeping.c:2177
 tick_do_update_jiffies64+0x28a/0x4b0 kernel/time/tick-sched.c:88
 tick_sched_do_timer kernel/time/tick-sched.c:135 [inline]
 tick_sched_timer+0xf8/0x520 kernel/time/tick-sched.c:1267
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0xc54/0x1630 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x451/0x13c0 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt+0x6b/0x250 arch/x86/kernel/apic/apic.c:1025
 smp_apic_timer_interrupt+0x5a/0x90 arch/x86/kernel/apic/apic.c:1053

Local variable description: ----timeout@futex_wait
Variable was created at:
 futex_wait+0xde/0xc20 kernel/futex.c:2613
 do_futex+0xcac/0x6c20 kernel/futex.c:3527
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/29 13:20 https://github.com/google/kmsan.git master 123906095e30 dba0b50e .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.