syzbot


INFO: rcu detected stall in sys_creat (4)

Status: auto-closed as invalid on 2021/12/03 06:38
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 425d, last: 425d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_creat 98 1412d 1503d 0/24 closed as dup on 2019/01/20 01:52
upstream INFO: rcu detected stall in sys_creat (2) 1 1096d 1096d 0/24 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in sys_creat (3) 1 867d 867d 0/24 auto-closed as invalid on 2020/10/17 06:02

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10498 ticks this GP) idle=3ad/1/0x4000000000000000 softirq=162062/162062 fqs=4963 
	(t=10500 jiffies g=302145 q=86801)
NMI backtrace for cpu 1
CPU: 1 PID: 27151 Comm: syz-executor.3 Not tainted 5.15.0-rc3-next-20211001-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3889 [inline]
 rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2608
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:charge_memcg+0x17c/0x360 mm/memcontrol.c:6724
Code: e2 01 00 00 48 8b 45 00 48 83 f8 ff 0f 84 55 01 00 00 48 8b 75 00 4c 89 e7 48 c1 ee 3a e8 cc 33 ff ff e8 87 d8 b9 ff fb 31 c0 <5b> 5d 41 5c 41 5d c3 e8 88 32 9f ff 31 d2 45 31 c9 45 31 c0 31 f6
RSP: 0018:ffffc900041af548 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 1ffffffff1fb6156
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffea00085b1540 R08: 0000000000000001 R09: ffffffff8fd17ad7
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88814076c000
R13: 0000000001100cca R14: 0000000000000080 R15: 0000000000000000
 __mem_cgroup_charge+0x27/0x90 mm/memcontrol.c:6732
 mem_cgroup_charge include/linux/memcontrol.h:720 [inline]
 __filemap_add_folio+0x724/0xe20 mm/filemap.c:899
 filemap_add_folio+0xab/0x1d0 mm/filemap.c:992
 do_read_cache_page+0x512/0x11a0 mm/filemap.c:3443
 read_mapping_page include/linux/pagemap.h:602 [inline]
 dir_get_page fs/minix/dir.c:70 [inline]
 minix_find_entry+0x203/0x7e0 fs/minix/dir.c:170
 minix_inode_by_name+0x6d/0x460 fs/minix/dir.c:454
 minix_lookup fs/minix/namei.c:30 [inline]
 minix_lookup+0x103/0x190 fs/minix/namei.c:22
 lookup_open.isra.0+0x69f/0x13d0 fs/namei.c:3260
 open_last_lookups fs/namei.c:3352 [inline]
 path_openat+0x9a5/0x2740 fs/namei.c:3558
 do_filp_open+0x1aa/0x400 fs/namei.c:3588
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_creat fs/open.c:1290 [inline]
 __se_sys_creat fs/open.c:1284 [inline]
 __x64_sys_creat+0xc9/0x120 fs/open.c:1284
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ff70a6d58d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff707c4c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007ff70a7d9f60 RCX: 00007ff70a6d58d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000140
RBP: 00007ff70a72fcb4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcde728dff R14: 00007ff707c4c300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	e2 01                	loop   0x3
   2:	00 00                	add    %al,(%rax)
   4:	48 8b 45 00          	mov    0x0(%rbp),%rax
   8:	48 83 f8 ff          	cmp    $0xffffffffffffffff,%rax
   c:	0f 84 55 01 00 00    	je     0x167
  12:	48 8b 75 00          	mov    0x0(%rbp),%rsi
  16:	4c 89 e7             	mov    %r12,%rdi
  19:	48 c1 ee 3a          	shr    $0x3a,%rsi
  1d:	e8 cc 33 ff ff       	callq  0xffff33ee
  22:	e8 87 d8 b9 ff       	callq  0xffb9d8ae
  27:	fb                   	sti
  28:	31 c0                	xor    %eax,%eax
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	5d                   	pop    %rbp
  2c:	41 5c                	pop    %r12
  2e:	41 5d                	pop    %r13
  30:	c3                   	retq
  31:	e8 88 32 9f ff       	callq  0xff9f32be
  36:	31 d2                	xor    %edx,%edx
  38:	45 31 c9             	xor    %r9d,%r9d
  3b:	45 31 c0             	xor    %r8d,%r8d
  3e:	31 f6                	xor    %esi,%esi

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2021/10/04 06:31 linux-next a25006a77348 db0f5787 .config log report info INFO: rcu detected stall in sys_creat
* Struck through repros no longer work on HEAD.