syzbot


INFO: rcu detected stall in do_symlinkat (2)

Status: auto-closed as invalid on 2021/10/26 01:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 589d, last: 496d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in do_symlinkat 1 701d 701d 0/24 auto-closed as invalid on 2021/04/04 02:44

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=108697, q=21)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295035455-4295024953), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g108697 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:26384 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0xc07/0x11f0 kernel/sched/core.c:5940
 schedule+0x14b/0x210 kernel/sched/core.c:6019
 schedule_timeout+0x1aa/0x2f0 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0x10fd/0x1720 kernel/rcu/tree.c:2169
 kthread+0x453/0x480 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 30519 Comm: syz-executor.1 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mark_lock+0x150/0x1eb0 kernel/locking/lockdep.c:4565
Code: 8a 04 38 84 c0 0f 85 df 0f 00 00 8a 43 02 24 03 3c 01 ba 09 00 00 00 83 da 00 41 bd 01 00 00 00 48 89 d0 48 89 54 24 08 89 d1 <41> d3 e5 48 89 74 24 30 48 8d 56 20 48 89 d0 48 c1 e8 03 48 89 44
RSP: 0018:ffffc90000dc0440 EFLAGS: 00000093
RAX: 0000000000000000 RBX: ffffffff8f87d1f8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8880174426d0 RDI: ffff888017441c40
RBP: ffffc90000dc06d0 R08: dffffc0000000000 R09: fffffbfff1f5e3b2
R10: fffffbfff1f5e3b2 R11: 0000000000000000 R12: 1ffff920001b8094
R13: 0000000000000001 R14: ffff888017441c40 R15: dffffc0000000000
FS:  000000000203e400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005632e3fd1b08 CR3: 00000000933c6000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4485 [inline]
 __lock_acquire+0xc5c/0x6100 kernel/locking/lockdep.c:4969
 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159
 debug_object_activate+0x97/0x6a0 lib/debugobjects.c:656
 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline]
 debug_activate kernel/time/hrtimer.c:475 [inline]
 enqueue_hrtimer kernel/time/hrtimer.c:982 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1554 [inline]
 __hrtimer_run_queues+0x594/0xa60 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:lock_acquire+0x1e7/0x4a0 kernel/locking/lockdep.c:5629
Code: 08 48 89 df e8 ba 6b 67 00 f6 84 24 81 00 00 00 02 0f 85 24 02 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2c 00 00 00 00 43 c7 44 2c 09 00 00 00 00 43 c7 44 2c 11
RSP: 0018:ffffc9000fa3f860 EFLAGS: 00000206
RAX: 1ffff92001f47f1c RBX: ffffc9000fa3f8e0 RCX: ffffffff816214eb
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000fa3f9c0 R08: dffffc0000000000 R09: fffffbfff1f5e3bb
R10: fffffbfff1f5e3bb R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92001f47f14 R14: 0000000000000001 R15: 0000000000000246
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:354 [inline]
 insert_inode_locked+0xde/0x490 fs/inode.c:1548
 __ext4_new_inode+0x39d7/0x5810 fs/ext4/ialloc.c:1266
 ext4_symlink+0x493/0x1000 fs/ext4/namei.c:3465
 vfs_symlink+0x396/0x530 fs/namei.c:4182
 do_symlinkat+0x251/0x510 fs/namei.c:4212
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465ef7
Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 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:00007ffc954dba28 EFLAGS: 00000206 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000465ef7
RDX: 00007ffc954dbb13 RSI: 00000000004bfd6e RDI: 00007ffc954dbb00
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc954db8c0
R10: 00007ffc954db777 R11: 0000000000000206 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffc954dbb00

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/07/28 01:11 upstream 7d549995d4e0 17d6ab15 .config log report info INFO: rcu detected stall in do_symlinkat
ci-upstream-kasan-gce-selinux-root 2021/06/10 05:07 upstream cd1245d75ce9 1ba81399 .config log report info INFO: rcu detected stall in do_symlinkat
ci-upstream-bpf-next-kasan-gce 2021/04/26 03:57 bpf-next 350a62ca065b 2a82f1b3 .config log report info INFO: rcu detected stall in do_symlinkat
* Struck through repros no longer work on HEAD.