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INFO: rcu detected stall in mbind

Status: auto-obsoleted due to no activity on 2026/05/09 19:34
Subsystems: mm kasan
[Documentation on labels]
First crash: 174d, last: 120d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
0317e3f3-9203-43bb-a8aa-1627024df344 repro ❓ INFO: rcu detected stall in mbind 2026/03/08 13:21 2026/03/08 13:21 2026/03/08 13:31 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_mbind (5) bpf 1 1 456d 456d 0/29 auto-obsoleted due to no activity on 2025/06/07 08:47
upstream INFO: rcu detected stall in sys_mbind mm 1 4 2601d 2631d 0/29 auto-closed as invalid on 2019/10/22 22:44
upstream INFO: rcu detected stall in sys_mbind (2) mm 1 1 2127d 2127d 0/29 auto-closed as invalid on 2020/11/09 09:33
upstream INFO: rcu detected stall in sys_mbind (4) mm 1 1 653d 653d 0/29 auto-obsoleted due to no activity on 2024/11/22 04:15
upstream INFO: rcu detected stall in sys_mbind (3) cgroups mm 1 1 725d 725d 0/29 auto-obsoleted due to no activity on 2024/08/12 04:57
linux-4.19 BUG: soft lockup in sys_mbind 1 syz error 1 1860d 1860d 0/1 upstream: reported syz repro on 2021/05/05 05:15

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5827/1:b..l P5842/2:b..l P6045/1:b..l P5889/1:b..l P5192/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=11561, q=1204 ncpus=2)
task:udevd           state:R  running task     stack:25312 pid:5192  tgid:5192  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127
 sock_def_readable+0x1eb/0x530 net/core/sock.c:3611
 __netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
 netlink_sendskb+0xa1/0x140 net/netlink/af_netlink.c:1269
 netlink_unicast+0x397/0x9e0 net/netlink/af_netlink.c:1359
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x820 net/socket.c:2592
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f878daa7407
RSP: 002b:00007ffe27a69490 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f878e1d0880 RCX: 00007f878daa7407
RDX: 0000000000000000 RSI: 00007ffe27a694f0 RDI: 0000000000000004
RBP: 000055e7f0a97850 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000ba
R13: 000055e7f0a8d9e0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:udevd           state:R  running task     stack:24088 pid:5889  tgid:5889  ppid:5192   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x130e/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49
RSP: 0018:ffffc9000414f798 EFLAGS: 00000217
RAX: 0000000000000000 RBX: ffffffff8f992e34 RCX: dffffc0000000000
RDX: ffffffff8f992e24 RSI: ffffffff90143374 RDI: ffffffff8bc08300
RBP: ffffffff8f992e24 R08: 0000000000000005 R09: ffffffff8df419e0
R10: dffffc0000000000 R11: fffff52000829f25 R12: ffffffff816ac883
R13: ffffffff8f992e24 R14: ffffc9000414f8c8 R15: ffffffff8f992e2c
 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 getname_flags+0xb8/0x540 fs/namei.c:146
 getname include/linux/fs.h:2498 [inline]
 getname_maybe_null include/linux/fs.h:2505 [inline]
 vfs_fstatat+0x43/0x170 fs/stat.c:370
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat fs/stat.c:536 [inline]
 __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f878db11b0a
RSP: 002b:00007ffe27a630f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 000055e7f0ababd1 RCX: 00007f878db11b0a
RDX: 00007ffe27a63100 RSI: 00007ffe27a63190 RDI: 00000000ffffff9c
RBP: 000055e7f0aa2830 R08: 000055e7f0ababd1 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 000055e7f0aa2920
R13: 00007ffe27a63190 R14: 000055e7f0a8e64c R15: 000055e7dea0cbcc
 </TASK>
task:syz.1.16        state:R  running task     stack:26232 pid:6045  tgid:6038  ppid:5826   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x20/0x3b0 kernel/locking/lockdep.c:5876
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 60 0a e0 10 <48> 89 44 24 28 0f 1f 44 00 00 65 8b 05 63 0a e0 10 83 f8 08 0f 83
RSP: 0018:ffffc900049b6e90 EFLAGS: 00000286
RAX: 50f774f7f25e7700 RBX: 00007f1a98813f01 RCX: 50f774f7f25e7700
RDX: ffffffff900c3600 RSI: ffffffff81743f85 RDI: ffffffff8df419e0
RBP: dffffc0000000000 R08: 0000000000000022 R09: ffffffff8df419e0
R10: dffffc0000000000 R11: ffffffff81ada000 R12: 00007f1a9964d038
R13: ffffffff81743f85 R14: ffffffff8df419e0 R15: ffffffff81743f85
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:165
 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
 alloc_migration_target_by_mpol+0x2e6/0x590 mm/mempolicy.c:1458
 migrate_folio_unmap mm/migrate.c:1214 [inline]
 migrate_pages_batch+0x801/0x35e0 mm/migrate.c:1890
 migrate_pages_sync mm/migrate.c:2007 [inline]
 migrate_pages+0x1b9a/0x28e0 mm/migrate.c:2116
 do_mbind mm/mempolicy.c:1609 [inline]
 kernel_mbind mm/mempolicy.c:1752 [inline]
 __do_sys_mbind mm/mempolicy.c:1826 [inline]
 __se_sys_mbind+0xa47/0xc40 mm/mempolicy.c:1822
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1a9878f749
RSP: 002b:00007f1a9964d038 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007f1a989e6090 RCX: 00007f1a9878f749
RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000200000001000
RBP: 00007f1a98813f91 R08: 0000000000000000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1a989e6128 R14: 00007f1a989e6090 R15: 00007ffc4322dd48
 </TASK>
task:syz-executor    state:R  running task     stack:20640 pid:5842  tgid:5842  ppid:5822   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:868 [inline]
RIP: 0010:page_ref_add_unless include/linux/page_ref.h:235 [inline]
RIP: 0010:folio_ref_add_unless include/linux/page_ref.h:248 [inline]
RIP: 0010:folio_try_get+0x3c/0x340 include/linux/page_ref.h:264
Code: f4 ad ff 48 8d 1d 00 00 00 00 48 c7 c7 e0 19 f4 8d 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 53 e8 38 16 a4 ff 48 83 c4 08 <e8> cf 59 61 09 89 c5 31 ff 89 c6 e8 a4 56 c7 ff 85 ed 74 10 e8 9b
RSP: 0018:ffffc9000410f4b0 EFLAGS: 00000292
RAX: 9ff0917aa8f23600 RBX: ffffffff81fa5e6c RCX: 9ff0917aa8f23600
RDX: 000000008eba6367 RSI: ffffffff8d978ed0 RDI: ffffffff8bc08360
RBP: ffffc9000410f630 R08: ffffffff81fa5e6c R09: ffffffff8df419e0
R10: 0000000000000406 R11: 0000000000000000 R12: ffffea0001421bc0
R13: fffffffffffffffe R14: ffffea0001421bc0 R15: ffffea0001421bc0
 find_get_entry mm/filemap.c:2076 [inline]
 find_lock_entries+0x24f/0xa60 mm/filemap.c:2166
 shmem_undo_range+0x254/0x1490 mm/shmem.c:1119
 shmem_truncate_range mm/shmem.c:1249 [inline]
 shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379
 evict+0x5f4/0xae0 fs/inode.c:837
 __dentry_kill+0x209/0x660 fs/dcache.c:670
 finish_dput+0xc9/0x480 fs/dcache.c:879
 __fput+0x68e/0xa70 fs/file_table.c:476
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6fdd98e3aa
RSP: 002b:00007ffccc73bbd0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f6fdd98e3aa
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffccc73bc2c R08: 0000000000000000 R09: 00007ffccc73b937
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00000000000927c0 R14: 000000000001b0c7 R15: 00007ffccc73bc80
 </TASK>
task:syz-executor    state:R  running task     stack:20952 pid:5827  tgid:5827  ppid:5825   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_pte_range mm/memory.c:1331 [inline]
 copy_pmd_range+0x74f2/0x7e00 mm/memory.c:1392
 copy_pud_range mm/memory.c:1429 [inline]
 copy_p4d_range mm/memory.c:1453 [inline]
 copy_page_range+0xb88/0x11d0 mm/memory.c:1535
 dup_mmap+0xf4a/0x1b80 mm/mmap.c:1827
 dup_mm kernel/fork.c:1529 [inline]
 copy_mm+0x13c/0x4b0 kernel/fork.c:1581
 copy_process+0x165d/0x3950 kernel/fork.c:2221
 kernel_clone+0x21e/0x820 kernel/fork.c:2651
 __do_sys_clone kernel/fork.c:2792 [inline]
 __se_sys_clone kernel/fork.c:2776 [inline]
 __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b12785e93
RSP: 002b:00007ffccf720ad8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b12785e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555584f567d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001b327 R15: 00007ffccf720c70
 </TASK>
rcu: rcu_preempt kthread starved for 10712 jiffies! g11561 f0x0 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:27784 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e 93 b4 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 a0 0c 00 f3 0f 1e fa fb f4 <e9> 33 93 b4 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 19fcae0f26f3bf00 RBX: ffffffff81978eba RCX: 19fcae0f26f3bf00
RDX: 0000000000000001 RSI: ffffffff8d7921b8 RDI: ffffffff8bc08360
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f821e70
R13: 1ffff110038d5b70 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c36c58a CR3: 00000000331c1000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1ea/0x520 kernel/sched/idle.c:332
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/16 01:54 upstream 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mbind
2026/02/08 19:32 linux-next 9845cf73f7db 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in mbind
* Struck through repros no longer work on HEAD.