syzbot


INFO: rcu detected stall in find_vma

Status: auto-closed as invalid on 2020/10/26 20:59
Reported-by: syzbot+f50b57e1a6f99410c2fe@syzkaller.appspotmail.com
First crash: 726d, last: 726d

Sample crash report:
INFO: rcu_sched detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=3137, c=3136, q=0)
All QSes seen, last rcu_sched kthread activity 10502 (4294980896-4294970394), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor.3  R  running task    29024 17068   6351 0x00000000
Call Trace:
 <IRQ>
 sched_show_task kernel/sched/core.c:5168 [inline]
 sched_show_task.cold+0x335/0x399 kernel/sched/core.c:5143
 print_other_cpu_stall kernel/rcu/tree.c:1501 [inline]
 check_cpu_stall kernel/rcu/tree.c:1616 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0xd3f/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle.isra.0+0x73/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x41/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x24b/0xb90 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5f0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x50 kernel/kcov.c:65
RSP: 0000:ffff8881c9237e40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: ffff88809260a0c0 RBX: 0000000000000002 RCX: ffffc90007101000
RDX: 0000000000040000 RSI: ffffffff8177edf6 RDI: ffff88809fba3da8
RBP: dffffc0000000000 R08: 0000000000000001 R09: 00000000000583e5
R10: ffff88809260a948 R11: ffff88809260a0c0 R12: ffff88809fba3d68
R13: ffff88805b527980 R14: 0000000023b13ce8 R15: ffff88809260a0c0
 vmacache_find+0x125/0x260 mm/vmacache.c:66
 find_vma+0x1c/0x140 mm/mmap.c:2149
 __do_page_fault+0x32d/0xb50 arch/x86/mm/fault.c:1388
 page_fault+0x45/0x50 arch/x86/entry/entry_64.S:1123
RIP: 0c38:0x4ce8ad
RSP: 50a400:000000000078bf00 EFLAGS: ffffffff
rcu_sched kthread starved for 10502 jiffies! g3137 c3136 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
rcu_sched       R  running task    29904     9      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x4df/0xe50 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb3d/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: rcu_preempt detected stalls on CPUs/tasks:
	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3637
	(detected by 0, t=10527 jiffies, g=5558, c=5557, q=287)
systemd-udevd   R  running task    26320  3637      1 0x00000100
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 preempt_schedule_notrace+0x99/0x120 kernel/sched/core.c:3582
 ___preempt_schedule_notrace+0x16/0x27
 rcu_is_watching+0x87/0xb0 kernel/rcu/tree.c:1131
 rcu_read_lock include/linux/rcupdate.h:630 [inline]
 __d_lookup+0x4a8/0x670 fs/dcache.c:2326
 lookup_fast+0x31f/0xe60 fs/namei.c:1641
 walk_component+0xc0/0xbc0 fs/namei.c:1821
 link_path_walk+0x80a/0x1080 fs/namei.c:2154
 path_lookupat.isra.0+0xcb/0x7b0 fs/namei.c:2342
 filename_lookup+0x18e/0x380 fs/namei.c:2377
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0xd1/0x160 fs/stat.c:185
 vfs_lstat include/linux/fs.h:3066 [inline]
 SYSC_newlstat fs/stat.c:350 [inline]
 SyS_newlstat+0x83/0xe0 fs/stat.c:344
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f542da05335
RSP: 002b:00007ffc393abe08 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 000055b06e7205d0 RCX: 00007f542da05335
RDX: 00007ffc393abe40 RSI: 00007ffc393abe40 RDI: 000055b06e71f5d0
RBP: 00007ffc393abf00 R08: 00007f542dcc41a8 R09: 0000000000001010
R10: 0000000000000020 R11: 0000000000000246 R12: 000055b06e71f5d0
R13: 000055b06e71f5ea R14: 000055b06e71ee15 R15: 000055b06e71ee1a
systemd-udevd   R  running task    26320  3637      1 0x00000100
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 preempt_schedule_notrace+0x99/0x120 kernel/sched/core.c:3582
 ___preempt_schedule_notrace+0x16/0x27
 rcu_is_watching+0x87/0xb0 kernel/rcu/tree.c:1131
 rcu_read_lock include/linux/rcupdate.h:630 [inline]
 __d_lookup+0x4a8/0x670 fs/dcache.c:2326
 lookup_fast+0x31f/0xe60 fs/namei.c:1641
 walk_component+0xc0/0xbc0 fs/namei.c:1821
 link_path_walk+0x80a/0x1080 fs/namei.c:2154
 path_lookupat.isra.0+0xcb/0x7b0 fs/namei.c:2342
 filename_lookup+0x18e/0x380 fs/namei.c:2377
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0xd1/0x160 fs/stat.c:185
 vfs_lstat include/linux/fs.h:3066 [inline]
 SYSC_newlstat fs/stat.c:350 [inline]
 SyS_newlstat+0x83/0xe0 fs/stat.c:344
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f542da05335
RSP: 002b:00007ffc393abe08 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 000055b06e7205d0 RCX: 00007f542da05335
RDX: 00007ffc393abe40 RSI: 00007ffc393abe40 RDI: 000055b06e71f5d0
RBP: 00007ffc393abf00 R08: 00007f542dcc41a8 R09: 0000000000001010
R10: 0000000000000020 R11: 0000000000000246 R12: 000055b06e71f5d0
R13: 000055b06e71f5ea R14: 000055b06e71ee15 R15: 000055b06e71ee1a
rcu_preempt kthread starved for 10527 jiffies! g5558 c5557 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
rcu_preempt     R  running task    29472     8      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x4df/0xe50 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb3d/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/06/28 20:58 linux-4.14.y b850307b279c a2cdad9d .config log report