syzbot


INFO: rcu detected stall in do_mkdirat (2)

Status: auto-closed as invalid on 2021/11/24 12:29
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 553d, last: 468d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in do_mkdirat 1 809d 809d 0/24 auto-closed as invalid on 2020/12/18 21:13

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=508701, q=36)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295285870-4295275368), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g508701 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:28032 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4681 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5938
 schedule+0xd3/0x270 kernel/sched/core.c:6017
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 19476 Comm: syz-executor.4 Not tainted 5.14.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unwind_next_frame+0xa/0x1ce0 arch/x86/kernel/unwind_orc.c:418
Code: e8 db c4 88 00 48 8b 04 24 eb bd 48 89 0c 24 e8 4c c4 88 00 48 8b 0c 24 e9 72 ff ff ff 0f 1f 00 48 b8 00 00 00 00 00 fc ff df <41> 57 41 56 49 89 fe 41 55 41 54 55 53 48 81 ec a0 00 00 00 48 c7
RSP: 0018:ffffc90000007708 EFLAGS: 00000202
RAX: dffffc0000000000 RBX: ffffffff816417f0 RCX: 0000000000000000
RDX: 1ffff92000000f11 RSI: ffffffff81650843 RDI: ffffc90000007710
RBP: ffffc90000007798 R08: ffffffff8deaa6da R09: 0000000000000001
R10: fffff52000000eed R11: 0000000000086088 R12: ffffc900000077c8
R13: 0000000000000000 R14: ffff88801f2dd4c0 R15: 0000000000000a20
FS:  00007ff18154d700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005131f0 CR3: 0000000078256000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x84/0xa0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:2956 [inline]
 slab_alloc mm/slub.c:2964 [inline]
 kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2969
 skb_clone+0x170/0x3c0 net/core/skbuff.c:1520
 hsr_create_tagged_frame+0x173/0xb60 net/hsr/hsr_forward.c:251
 hsr_forward_do net/hsr/hsr_forward.c:417 [inline]
 hsr_forward_skb+0x84c/0x1620 net/hsr/hsr_forward.c:578
 send_hsr_supervision_frame+0x60b/0x8d0 net/hsr/hsr_device.c:324
 hsr_announce+0x109/0x330 net/hsr/hsr_device.c:382
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:debug_spin_lock_after kernel/locking/spinlock_debug.c:92 [inline]
RIP: 0010:do_raw_spin_lock+0x17b/0x2b0 kernel/locking/spinlock_debug.c:115
Code: 0f b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d9 00 00 00 4c 89 ea 44 89 75 08 48 b8 00 00 00 00 00 fc ff df <48> c1 ea 03 65 4c 8b 24 25 00 f0 01 00 80 3c 02 00 0f 85 e4 00 00
RSP: 0018:ffffc90002e3f9c8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 1ffff920005c7f3a RCX: ffffffff815b9610
RDX: ffff88801a5677c8 RSI: 0000000000000004 RDI: ffffc90002e3f9f0
RBP: ffff88801a5677b8 R08: 0000000000000001 R09: 0000000000000003
R10: fffff520005c7f3e R11: 0000000000000000 R12: ffff88801a5677c0
R13: ffff88801a5677c8 R14: 0000000000000000 R15: 0000000000000000
 spin_lock include/linux/spinlock.h:354 [inline]
 __find_get_block_slow fs/buffer.c:206 [inline]
 __find_get_block fs/buffer.c:1308 [inline]
 __find_get_block+0x4df/0xdb0 fs/buffer.c:1302
 sb_find_get_block include/linux/buffer_head.h:340 [inline]
 recently_deleted fs/ext4/ialloc.c:687 [inline]
 find_inode_bit+0x230/0x580 fs/ext4/ialloc.c:729
 __ext4_new_inode+0xc4d/0x5c40 fs/ext4/ialloc.c:1064
 ext4_mkdir+0x33a/0xb20 fs/ext4/namei.c:2921
 vfs_mkdir+0x52e/0x760 fs/namei.c:3823
 do_mkdirat+0x284/0x310 fs/namei.c:3848
 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: 0033:0x4665e9
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:00007ff18154d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffe8aaabc8f R14: 00007ff18154d300 R15: 0000000000022000
----------------
Code disassembly (best guess):
   0:	e8 db c4 88 00       	callq  0x88c4e0
   5:	48 8b 04 24          	mov    (%rsp),%rax
   9:	eb bd                	jmp    0xffffffc8
   b:	48 89 0c 24          	mov    %rcx,(%rsp)
   f:	e8 4c c4 88 00       	callq  0x88c460
  14:	48 8b 0c 24          	mov    (%rsp),%rcx
  18:	e9 72 ff ff ff       	jmpq   0xffffff8f
  1d:	0f 1f 00             	nopl   (%rax)
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	41 57                	push   %r15 <-- trapping instruction
  2c:	41 56                	push   %r14
  2e:	49 89 fe             	mov    %rdi,%r14
  31:	41 55                	push   %r13
  33:	41 54                	push   %r12
  35:	55                   	push   %rbp
  36:	53                   	push   %rbx
  37:	48 81 ec a0 00 00 00 	sub    $0xa0,%rsp
  3e:	48                   	rex.W
  3f:	c7                   	.byte 0xc7

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-bpf-next-kasan-gce 2021/08/26 12:20 bpf-next eb529c5b10b9 b599f2fc .config log report info INFO: rcu detected stall in do_mkdirat
ci-upstream-bpf-next-kasan-gce 2021/08/25 21:00 bpf-next 3bbc8ee7c363 b599f2fc .config log report info INFO: rcu detected stall in do_mkdirat
ci-upstream-bpf-next-kasan-gce 2021/07/13 05:46 bpf-next 97eb31384af9 f415556d .config log report info INFO: rcu detected stall in do_mkdirat
ci-upstream-bpf-next-kasan-gce 2021/06/08 13:52 bpf-next cf68fa431d5d b718257f .config log report info INFO: rcu detected stall in do_mkdirat
ci-upstream-linux-next-kasan-gce-root 2021/06/02 19:58 linux-next a1f92694393a 0740de69 .config log report info INFO: rcu detected stall in do_mkdirat
* Struck through repros no longer work on HEAD.