syzbot


INFO: rcu detected stall in dput

Status: upstream: reported on 2025/06/17 20:59
Reported-by: syzbot+d1665e7f42dee637973f@syzkaller.appspotmail.com
First crash: 142d, last: 7d14h
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in dput (2) 1 48 1d11h 527d 0/3 upstream: reported on 2024/05/28 13:43
upstream INFO: rcu detected stall in dput (4) kvm 1 C error error 2 1427d 1787d 0/29 closed as invalid on 2022/02/08 10:37
linux-5.15 INFO: rcu detected stall in dput (3) 1 18 4d12h 332d 0/3 upstream: reported on 2024/12/09 17:03
upstream INFO: rcu detected stall in dput (3) mm 1 1 2129d 2129d 0/29 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in dput (8) fs 1 C done 526 2d14h 676d 0/29 upstream: reported C repro on 2023/12/31 19:35
linux-5.15 INFO: rcu detected stall in dput 1 2 800d 840d 0/3 auto-obsoleted due to no activity on 2023/12/08 00:28
upstream INFO: rcu detected stall in dput (6) fs 1 2 1101d 1160d 0/29 auto-obsoleted due to no activity on 2023/01/16 04:13
linux-5.15 INFO: rcu detected stall in dput (2) 1 10 459d 601d 0/3 auto-obsoleted due to no activity on 2024/11/12 09:55
upstream INFO: rcu detected stall in dput (5) fs 1 1 1297d 1297d 0/29 auto-closed as invalid on 2022/07/18 12:41
linux-6.1 INFO: rcu detected stall in dput 1 1 848d 848d 0/3 auto-obsoleted due to no activity on 2023/10/20 22:44
upstream INFO: rcu detected stall in dput fs 1 1 2164d 2164d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in dput (2) mm 1 2 2129d 2129d 0/29 closed as invalid on 2020/01/08 05:33

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10921/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=53313, q=107 ncpus=2)
task:syz.3.1031      state:R  running task     stack:25032 pid:10921 ppid:5789   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x30/0x60 kernel/kcov.c:216
Code: 04 24 65 48 8b 0d 20 28 7e 7e 65 8b 15 21 28 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c <8b> 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48
RSP: 0018:ffffc90005346df0 EFLAGS: 00000246
RAX: ffffffff813aa367 RBX: ffffc90005346f80 RCX: ffff88807d068000
RDX: 0000000000000000 RSI: ffffffff81f34366 RDI: ffffc90005346ec8
RBP: ffffc90005346f50 R08: ffffc90005346f90 R09: 0000000000000006
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90005346ec8
R13: dffffc0000000000 R14: ffffffff81746cb0 R15: ffffc90005346ec8
 unwind_next_frame+0x27/0x2970 arch/x86/kernel/unwind_orc.c:469
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf7/0x1f0 mm/page_owner.c:128
 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2475
 release_pages+0x1fa0/0x2220 mm/swap.c:1022
 __folio_batch_release+0x71/0xe0 mm/swap.c:1042
 folio_batch_release include/linux/pagevec.h:83 [inline]
 shmem_undo_range+0x5d0/0x1a40 mm/shmem.c:1027
 shmem_truncate_range mm/shmem.c:1136 [inline]
 shmem_evict_inode+0x273/0xa70 mm/shmem.c:1265
 evict+0x486/0x870 fs/inode.c:705
 __dentry_kill+0x431/0x650 fs/dcache.c:611
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xfe/0x1e0 fs/dcache.c:918
 __fput+0x5e5/0x970 fs/file_table.c:392
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x90b/0x23c0 kernel/exit.c:883
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb697d8da7f
RSP: 002b:00007fb698d17df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: 0000000001389000 RBX: 00000000013bd7ef RCX: 00007fb697d8da7f
RDX: 00000000013bd7ef RSI: 00007fb68dbf7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005523
R10: 00000000000003ca R11: 0000000000000293 R12: 0000000000000003
R13: 00007fb698d17ef0 R14: 00007fb698d17eb0 R15: 00007fb68dbf7000
 </TASK>
rcu: rcu_preempt kthread starved for 10563 jiffies! g53313 f0x0 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:26568 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 10947 Comm: syz.4.1037 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline]
RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:196
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 f3 0f 1e fa 89 f6 31 d2 e9 57 12 19 03 0f 1f 80 00 00 00
RSP: 0018:ffffc900051afcd8 EFLAGS: 00000246
RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
RBP: 0000000000000000 R08: ffffc900051afc47 R09: 1ffff92000a35f88
R10: dffffc0000000000 R11: fffff52000a35f89 R12: ffff8880b8e35001
R13: dffffc0000000000 R14: ffff8880b8e35050 R15: 0000000000000020
FS:  00007f78d60c46c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c418182 CR3: 000000002b489000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 __apic_send_IPI_self arch/x86/include/asm/apic.h:454 [inline]
 arch_irq_work_raise+0x68/0x70 arch/x86/kernel/irq_work.c:31
 irq_work_queue+0x99/0x140 kernel/irq_work.c:124
 bpf_send_signal_common+0x2b6/0x420 kernel/trace/bpf_trace.c:875
 ____bpf_send_signal kernel/trace/bpf_trace.c:884 [inline]
 bpf_send_signal+0x19/0x20 kernel/trace/bpf_trace.c:882
 bpf_prog_7ba5217f62dcd359+0x40/0x44
 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
 __bpf_prog_run include/linux/filter.h:612 [inline]
 bpf_prog_run include/linux/filter.h:619 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361
 trace_sys_enter+0x69/0x80 include/trace/events/syscalls.h:18
 syscall_trace_enter+0xf0/0x150 kernel/entry/common.c:81
 do_syscall_64+0x28/0xb0 arch/x86/entry/common.c:77
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f78d518efc9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f78d60c40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f78d53e6188 RCX: 00007f78d518efc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f78d53e6188
RBP: 00007f78d53e6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78d53e6218 R14: 00007ffe23f6fe00 R15: 00007ffe23f6fee8
 </TASK>

Crashes (37):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/30 11:02 linux-6.6.y e5bbb12db2c7 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/10/28 21:11 linux-6.6.y 4a243110dc88 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/10/27 21:53 linux-6.6.y 4a243110dc88 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/09/26 09:13 linux-6.6.y 147338df3487 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/09/22 23:04 linux-6.6.y af1544b5d072 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/09/16 16:40 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/08/24 23:15 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/24 01:34 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/23 08:46 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/22 04:00 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/20 15:45 linux-6.6.y bb9c90ab9c5a 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/15 22:08 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/14 14:56 linux-6.6.y 3a8ababb8b6a 5d8c2ac2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/12 04:19 linux-6.6.y 3a8ababb8b6a c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/08/11 20:12 linux-6.6.y 3a8ababb8b6a c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/10 23:45 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/09 12:07 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/05 11:17 linux-6.6.y 3a8ababb8b6a 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/04 14:15 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/04 09:05 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/08/03 07:09 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/30 03:49 linux-6.6.y dbcb8d8e4163 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/29 17:07 linux-6.6.y dbcb8d8e4163 c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/28 13:28 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/28 13:28 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/27 23:25 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/26 08:06 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/07/26 01:07 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/20 15:10 linux-6.6.y d96eb99e2f0e 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/19 16:43 linux-6.6.y d96eb99e2f0e 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/14 19:21 linux-6.6.y 9247f4e6573a d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/13 01:16 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/12 15:24 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/09 11:42 linux-6.6.y a5df3a702b2c f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/08 07:59 linux-6.6.y a5df3a702b2c 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in dput
2025/07/03 10:09 linux-6.6.y 3f5b4c104b7d 115ceea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
2025/06/17 20:59 linux-6.6.y c2603c511feb e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in dput
* Struck through repros no longer work on HEAD.