syzbot


INFO: rcu detected stall in __do_softirq

Status: upstream: reported on 2024/06/06 06:04
Reported-by: syzbot+55d93318bf4f78f520fd@syzkaller.appspotmail.com
First crash: 12d, last: 12d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in __do_softirq 2 231d 250d 0/3 auto-obsoleted due to no activity on 2024/02/08 12:45
linux-4.19 INFO: rcu detected stall in __do_softirq (2) 9 1374d 1560d 0/1 auto-closed as invalid on 2021/01/10 17:25
linux-4.14 INFO: rcu detected stall in __do_softirq 1 1827d 1827d 0/1 auto-closed as invalid on 2019/10/25 08:47
linux-4.19 INFO: rcu detected stall in __do_softirq 2 1762d 1826d 0/1 auto-closed as invalid on 2019/12/20 09:57
upstream INFO: rcu detected stall in __do_softirq net syz done 35 545d 1778d 0/27 auto-obsoleted due to no activity on 2023/04/21 04:43
linux-4.14 BUG: soft lockup in __do_softirq syz error 3 1140d 1182d 0/1 upstream: reported syz repro on 2021/03/23 20:32

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2655 jiffies s: 4869 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3572 Comm: syz-executor.0 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:debug_object_activate+0x1d9/0x4e0 lib/debugobjects.c:705
Code: 23 02 00 00 48 81 fb 00 f0 ff ff 0f 87 3e 02 00 00 4c 8d 73 10 4c 89 f5 48 c1 ed 03 42 0f b6 44 3d 00 84 c0 0f 85 5b 02 00 00 <41> 8b 06 8d 48 ff 83 f9 02 0f 82 ed 00 00 00 83 c0 fd 83 f8 01 0f
RSP: 0018:ffffc900001e0a08 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880587b7b98 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc900001e08e0
RBP: 1ffff1100b0f6f75 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff91f46fb0
R13: ffff8880200e6340 R14: ffff8880587b7ba8 R15: dffffc0000000000
FS:  00005555558f5480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1a0b376440 CR3: 000000005bf0e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline]
 debug_activate kernel/time/hrtimer.c:475 [inline]
 enqueue_hrtimer+0x30/0x410 kernel/time/hrtimer.c:1084
 __run_hrtimer kernel/time/hrtimer.c:1703 [inline]
 __hrtimer_run_queues+0x728/0xe50 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:__do_softirq+0x1f3/0xa4c kernel/softirq.c:559
Code: 00 00 00 44 0f b7 f3 48 c7 c7 60 fa ea 8a e8 a4 1f cb ff 65 66 c7 05 9a 9d 43 75 00 00 e8 b5 4d d1 f6 fb 49 c7 c7 c0 a0 e0 8c <44> 89 74 24 54 b8 ff ff ff ff 0f bc 44 24 54 41 89 c4 41 ff c4 0f
RSP: 0018:ffffc900001e0e00 EFLAGS: 00000286
RAX: 3d0b1b3c6ace6100 RBX: 0000000000400386 RCX: ffffffff816acf0a
RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: ffffffff8b3d45e0
RBP: ffffc900001e0f30 R08: dffffc0000000000 R09: fffffbfff2093846
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888017763b80
R13: 1ffff9200003c1e8 R14: 0000000000000386 R15: ffffffff8ce0a0c0
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: c1 bc f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 fe 3b d5 f6 48 89 df e8 66 79 d6 f6 e8 31 04 fc f6 fb bf 01 00 00 00 <e8> 56 08 c9 f6 65 8b 05 c7 23 6d 75 85 c0 74 02 5b c3 e8 f4 48 6b
RSP: 0018:ffffc90003b4f7d8 EFLAGS: 00000286
RAX: 3d0b1b3c6ace6100 RBX: ffff888053949cb0 RCX: ffffffff816acf0a
RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: 0000000000000001
RBP: 1ffff1100a729395 R08: dffffc0000000000 R09: fffffbfff2093846
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffea0001975f00
R13: 000000000000000b R14: ffffea0001975f00 R15: ffff888053949ca8
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 filemap_remove_folio+0x10d/0x2e0 mm/filemap.c:256
 truncate_inode_folio+0x59/0x70 mm/truncate.c:195
 shmem_undo_range+0x570/0x2390 mm/shmem.c:942
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x265/0xa60 mm/shmem.c:1171
 evict+0x2a4/0x620 fs/inode.c:666
 __dentry_kill+0x436/0x650 fs/dcache.c:607
 dentry_kill+0xbb/0x290
 dput+0xfb/0x1d0 fs/dcache.c:914
 __fput+0x5e4/0x890 fs/file_table.c:328
 task_work_run+0x246/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f67bcc7e297
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffef909abf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f67bcc7e297
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffef909acb0
RBP: 00007ffef909acb0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffef909bd60
R13: 00007f67bccd9636 R14: 0000000000019787 R15: 0000000000000004
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/06 06:04 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in __do_softirq
* Struck through repros no longer work on HEAD.