syzbot

 sign-in | mailing list | source | docs
🐞 Open [1505]
≡ Subsystems
🐞 Fixed [6512]
🐞 Invalid [16564]
⬇ Missing Backports [204]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

INFO: rcu detected stall in kernfs_fop_read_iter

Status: auto-obsoleted due to no activity on 2022/11/04 01:43
Subsystems: kernel
[Documentation on labels]
First crash: 1107d, last: 1107d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in kernfs_fop_read_iter (3) kernfs 1 6 422d 602d 0/29 auto-obsoleted due to no activity on 2024/09/18 21:50
upstream INFO: rcu detected stall in kernfs_fop_read_iter (2) kernel 1 1 816d 816d 0/29 auto-obsoleted due to no activity on 2023/08/22 18:06
upstream INFO: rcu detected stall in kernfs_fop_read_iter (4) usb 1 syz 14 120d 322d 0/29 auto-obsoleted due to no activity on 2025/07/28 14:35
android-5-15 BUG: soft lockup in kernfs_fop_read_iter 1 1 468d 468d 0/2 auto-obsoleted due to no activity on 2024/08/04 18:27

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (2 ticks this GP) idle=15d/1/0x4000000000000000 softirq=161910/161910 fqs=0 
	(detected by 1, t=14354 jiffies, g=263449, q=436 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2977 Comm: udevd Not tainted 5.19.0-rc8-syzkaller-00130-g8eaa1d110800 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline]
RIP: 0010:kasan_check_range+0x9/0x180 mm/kasan/generic.c:189
Code: b6 f5 bf 00 08 00 00 89 43 0c e8 72 e4 ff ff 89 43 08 5b 5d 41 5c c3 66 2e 0f 1f 84 00 00 00 00 00 48 85 f6 0f 84 3c 01 00 00 <49> 89 f9 41 54 44 0f b6 c2 49 01 f1 55 53 0f 82 18 01 00 00 48 b8
RSP: 0018:ffffc90000007ab8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 000000000000005b RCX: ffffffff815df792
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90685908
RBP: 0000000000000002 R08: dffffc0000000000 R09: ffffffff90685907
R10: fffffbfff20d0b20 R11: 0000000000000001 R12: 0000000000000003
R13: ffff88807dff5880 R14: ffff88807dff62e0 R15: dffffc0000000000
FS:  00007f216acf7840(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ef22000 CR3: 0000000025cb9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:227 [inline]
 check_wait_context kernel/locking/lockdep.c:4752 [inline]
 __lock_acquire+0x6f2/0x5660 kernel/locking/lockdep.c:5003
 lock_acquire kernel/locking/lockdep.c:5665 [inline]
 lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
 debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:658
 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline]
 debug_activate kernel/time/hrtimer.c:475 [inline]
 enqueue_hrtimer+0x27/0x3e0 kernel/time/hrtimer.c:1084
 __run_hrtimer kernel/time/hrtimer.c:1702 [inline]
 __hrtimer_run_queues+0xb02/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc90002d4faf0 EFLAGS: 00010246
RAX: ffff888077654000 RBX: 0000000000000001 RCX: 0000000000000f80
RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffff888077654080
RBP: ffff888011842140 R08: 0000000000000000 R09: ffff888077654000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000dc0 R14: 0000000000000a20 R15: 0000000000000dc0
 slab_post_alloc_hook mm/slab.h:752 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 kmem_cache_alloc_trace+0x290/0x3f0 mm/slub.c:3282
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 uevent_show+0x159/0x380 drivers/base/core.c:2398
 dev_attr_show+0x4b/0x90 drivers/base/core.c:2106
 sysfs_kf_seq_show+0x219/0x3d0 fs/sysfs/file.c:59
 seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230
 kernfs_fop_read_iter+0x506/0x6e0 fs/kernfs/file.c:235
 call_read_iter include/linux/fs.h:2052 [inline]
 new_sync_read+0x384/0x5f0 fs/read_write.c:401
 vfs_read+0x492/0x5d0 fs/read_write.c:482
 ksys_read+0x127/0x250 fs/read_write.c:620
 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+0x63/0xcd
RIP: 0033:0x7f216a9258fe
Code: c0 e9 e6 fe ff ff 50 48 8d 3d 0e c7 09 00 e8 c9 cf 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007ffdba0e6c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055763d4f8900 RCX: 00007f216a9258fe
RDX: 0000000000001000 RSI: 000055763d4f9e20 RDI: 000000000000000c
RBP: 00007f216a9f2380 R08: 000000000000000c R09: 00007f216a9f5a60
R10: 0000000000000063 R11: 0000000000000246 R12: 000055763d4f8900
R13: 0000000000000d68 R14: 00007f216a9f1780 R15: 0000000000000d68
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 14353 jiffies! g263449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=88427
rcu: rcu_preempt kthread starved for 14354 jiffies! g263449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28656 pid:   16 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0xa00/0x4b50 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1999
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2187
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
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: 2977 Comm: udevd Not tainted 5.19.0-rc8-syzkaller-00130-g8eaa1d110800 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5403 [inline]
RIP: 0010:lock_is_held_type+0x63/0x140 kernel/locking/lockdep.c:5708
Code: 00 41 8b 94 24 5c 0a 00 00 85 d2 0f 85 b1 00 00 00 48 89 fd 41 89 f6 9c 8f 04 24 fa 48 c7 c7 80 88 cc 89 31 db e8 dd 0d 00 00 <41> 8b 84 24 58 0a 00 00 4d 8d ac 24 60 0a 00 00 65 ff 05 7e f0 8a
RSP: 0018:ffffc90000007c28 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000010003 RDI: 0000000000000000
RBP: ffffffff8bd87120 R08: 0000000000000000 R09: ffffffff8dbbc497
R10: fffffbfff1b77892 R11: 0000000000000001 R12: ffff88807dff5880
R13: 00000000ffffffff R14: 00000000ffffffff R15: ffff88807345cb40
FS:  00007f216acf7840(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ef22000 CR3: 0000000025cb9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_is_held include/linux/lockdep.h:279 [inline]
 rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x560/0x780 kernel/locking/lockdep.c:5676
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194
 debug_object_deactivate lib/debugobjects.c:754 [inline]
 debug_object_deactivate+0x264/0x300 lib/debugobjects.c:720
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate kernel/time/hrtimer.c:481 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
 __hrtimer_run_queues+0x3f8/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc90002d4faf0 EFLAGS: 00010246
RAX: ffff888077654000 RBX: 0000000000000001 RCX: 0000000000000f80
RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffff888077654080
RBP: ffff888011842140 R08: 0000000000000000 R09: ffff888077654000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000dc0 R14: 0000000000000a20 R15: 0000000000000dc0
 slab_post_alloc_hook mm/slab.h:752 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 kmem_cache_alloc_trace+0x290/0x3f0 mm/slub.c:3282
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 uevent_show+0x159/0x380 drivers/base/core.c:2398
 dev_attr_show+0x4b/0x90 drivers/base/core.c:2106
 sysfs_kf_seq_show+0x219/0x3d0 fs/sysfs/file.c:59
 seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230
 kernfs_fop_read_iter+0x506/0x6e0 fs/kernfs/file.c:235
 call_read_iter include/linux/fs.h:2052 [inline]
 new_sync_read+0x384/0x5f0 fs/read_write.c:401
 vfs_read+0x492/0x5d0 fs/read_write.c:482
 ksys_read+0x127/0x250 fs/read_write.c:620
 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+0x63/0xcd
RIP: 0033:0x7f216a9258fe
Code: c0 e9 e6 fe ff ff 50 48 8d 3d 0e c7 09 00 e8 c9 cf 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007ffdba0e6c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055763d4f8900 RCX: 00007f216a9258fe
RDX: 0000000000001000 RSI: 000055763d4f9e20 RDI: 000000000000000c
RBP: 00007f216a9f2380 R08: 000000000000000c R09: 00007f216a9f5a60
R10: 0000000000000063 R11: 0000000000000246 R12: 000055763d4f8900
R13: 0000000000000d68 R14: 00007f216a9f1780 R15: 0000000000000d68
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/08/06 01:38 net-old 8eaa1d110800 e853abd9 .config console log report info ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kernfs_fop_read_iter
* Struck through repros no longer work on HEAD.