syzbot


INFO: task hung in iterate_supers

Status: upstream: reported on 2023/03/10 21:24
Reported-by: syzbot+3f0d6aae71bcc34c89df@syzkaller.appspotmail.com
First crash: 711d, last: 3d22h
Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in iterate_supers 1 2304d 2142d 0/1 auto-closed as invalid on 2019/04/28 09:45
linux-4.14 INFO: task hung in iterate_supers 16 1512d 2127d 0/1 auto-closed as invalid on 2021/04/29 12:11
linux-4.19 INFO: task hung in iterate_supers (2) 1 1714d 1714d 0/1 auto-closed as invalid on 2020/10/09 12:15
upstream INFO: task hung in iterate_supers 9p C error 5109 7h46m 2416d 0/28 upstream: reported C repro on 2018/07/10 10:30
linux-5.15 INFO: task hung in iterate_supers origin:lts-only C 253 21m 714d 0/3 upstream: reported C repro on 2023/03/08 18:22
linux-4.14 INFO: task hung in iterate_supers (2) 1 726d 726d 0/1 upstream: reported on 2023/02/24 15:59
linux-4.19 INFO: task hung in iterate_supers 7 1846d 2034d 0/1 auto-closed as invalid on 2020/05/29 21:42
linux-4.19 INFO: task hung in iterate_supers (3) vfs reiserfs ntfs syz 378 715d 1522d 0/1 upstream: reported syz repro on 2020/12/20 03:38
android-49 INFO: task hung in iterate_supers 19 2366d 2466d 0/3 auto-closed as invalid on 2019/02/25 14:49
android-414 INFO: task hung in iterate_supers (2) 1 2123d 2123d 0/1 auto-closed as invalid on 2019/10/25 08:49
upstream INFO: task can't die in iterate_supers (2) ceph fs 1 1346d 1342d 0/28 auto-closed as invalid on 2021/08/13 03:51

Sample crash report:
INFO: task syz.7.1175:9767 blocked for more than 144 seconds.
      Not tainted 6.1.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1175      state:D stack:25408 pid:9767  ppid:5676   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline]
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x6ff/0xa30 kernel/locking/rwsem.c:1522
 iterate_supers+0xac/0x1e0 fs/super.c:755
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f09ae18cde9
RSP: 002b:00007f09aef2c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f09ae3a5fa0 RCX: 00007f09ae18cde9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f09ae3a5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f09ae3a5fa0 R15: 00007ffe4acbbd58
 </TASK>
INFO: task syz.7.1175:9768 blocked for more than 144 seconds.
      Not tainted 6.1.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1175      state:D stack:28616 pid:9768  ppid:5676   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline]
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x6ff/0xa30 kernel/locking/rwsem.c:1522
 iterate_supers+0xac/0x1e0 fs/super.c:755
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f09ae18cde9
RSP: 002b:00007f09aef0b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f09ae3a6080 RCX: 00007f09ae18cde9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f09ae3a6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f09ae3a6080 R15: 00007ffe4acbbd58
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32e850 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32f050 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
1 lock held by klogd/3612:
 #0: ffff8880b8f3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
2 locks held by getty/4009:
 #0: ffff88814d09e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4258:
 #0: ffff88807a5900e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by syz.7.1175/9767:
 #0: ffff88807a5900e0 (&type->s_umount_key#49){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.7.1175/9768:
 #0: ffff88807a5900e0 (&type->s_umount_key#49){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.8.1531/11112:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 11273 Comm: syz.5.1586 Not tainted 6.1.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: e8 25 00 00 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d f8 fb 15 0d 48 89 de 5b e9 b7 7f 56 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d 44 dc 77 7e 65 8b 15 45 dc 77 7e 81 e2 00
RSP: 0018:ffffc90003aa6e58 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff8880259e9dc0
RDX: ffff8880259e9dc0 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff81eb0d46 R09: ffffed100342be2e
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88801a15f1b0 R14: ffff88801a15f190 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68a7f78ab8 CR3: 000000003138d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __set_page_owner_handle+0x386/0x3d0 mm/page_owner.c:182
 __set_page_owner+0x43/0x60 mm/page_owner.c:195
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605
 __get_free_pages+0x8/0x30 mm/page_alloc.c:5655
 tlb_next_batch mm/mmu_gather.c:31 [inline]
 __tlb_remove_page_size+0x1fa/0x3e0 mm/mmu_gather.c:97
 __tlb_remove_page include/asm-generic/tlb.h:444 [inline]
 zap_pte_range mm/memory.c:1456 [inline]
 zap_pmd_range mm/memory.c:1574 [inline]
 zap_pud_range mm/memory.c:1603 [inline]
 zap_p4d_range mm/memory.c:1624 [inline]
 unmap_page_range+0x1316/0x2740 mm/memory.c:1645
 unmap_vmas+0x48b/0x640 mm/memory.c:1730
 exit_mmap+0x249/0x980 mm/mmap.c:3238
 __mmput+0x115/0x3c0 kernel/fork.c:1200
 exit_mm+0x226/0x300 kernel/exit.c:565
 do_exit+0x9f1/0x26a0 kernel/exit.c:858
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 get_signal+0x16cb/0x17a0 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 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: 0033:0x7f3299f8cde9
Code: Unable to access opcode bytes at 0x7f3299f8cdbf.
RSP: 002b:00007f329ade8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f329a1a6160 RCX: 00007f3299f8cde9
RDX: 0000000000010106 RSI: 00004000000000c0 RDI: 0000000000000003
RBP: 00007f329a00e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f329a1a6160 R15: 00007ffd1903db48
 </TASK>

Crashes (252):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/15 15:03 linux-6.1.y 0cbb5f65e52f 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/02/14 11:57 linux-6.1.y 0cbb5f65e52f d9a046cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/02/07 23:26 linux-6.1.y 0cbb5f65e52f ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/02/07 15:19 linux-6.1.y 0cbb5f65e52f 53657d1b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/02/01 04:27 linux-6.1.y 75cefdf153f5 aa47157c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/31 20:20 linux-6.1.y 75cefdf153f5 aa47157c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/27 19:49 linux-6.1.y 75cefdf153f5 d99a33ad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/24 00:51 linux-6.1.y 75cefdf153f5 521b0ce3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/22 20:08 linux-6.1.y f4f677285b38 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/15 08:53 linux-6.1.y c63962be84ef 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/07 02:42 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/02 07:38 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/01/01 15:01 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/31 05:08 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/25 05:58 linux-6.1.y 29f02ec58a94 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/22 19:59 linux-6.1.y 29f02ec58a94 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/15 02:21 linux-6.1.y 52f863f820fd 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/14 23:47 linux-6.1.y 52f863f820fd 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/13 16:38 linux-6.1.y e4d90d63d385 3547e30f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/11 22:26 linux-6.1.y e4d90d63d385 ff949d25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/12/05 02:08 linux-6.1.y e4d90d63d385 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/11/29 04:13 linux-6.1.y e4d90d63d385 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/11/26 07:40 linux-6.1.y e4d90d63d385 11dbc254 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/11/20 02:14 linux-6.1.y b67dc5c9ade9 7d02db5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/11/11 22:23 linux-6.1.y d7039b844a1c 0c4b1325 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/11/08 09:52 linux-6.1.y 7c15117f9468 179b040e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/11/06 23:27 linux-6.1.y 7c15117f9468 df3dc63b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/30 11:14 linux-6.1.y 7ec6f9fa3d97 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/29 10:46 linux-6.1.y 7ec6f9fa3d97 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/24 22:07 linux-6.1.y 7ec6f9fa3d97 0d144d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/23 19:45 linux-6.1.y 7ec6f9fa3d97 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/18 06:59 linux-6.1.y 54d90d17e8ce 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/12 10:23 linux-6.1.y aa4cd140bba5 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/07 12:43 linux-6.1.y aa4cd140bba5 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/07 09:32 linux-6.1.y aa4cd140bba5 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/04 12:23 linux-6.1.y aa4cd140bba5 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/02 20:51 linux-6.1.y aa4cd140bba5 02f9582a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/10/01 10:18 linux-6.1.y aa4cd140bba5 bbd4e0a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/09/24 22:44 linux-6.1.y e526b12bf916 5643e0e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/09/20 13:40 linux-6.1.y e526b12bf916 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2024/09/20 02:26 linux-6.1.y e526b12bf916 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
2025/02/15 20:47 linux-6.1.y 0cbb5f65e52f 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in iterate_supers
2024/12/03 09:47 linux-6.1.y e4d90d63d385 578925bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in iterate_supers
2024/11/03 18:20 linux-6.1.y 7c15117f9468 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in iterate_supers
2023/03/10 21:23 linux-6.1.y 8a923980a190 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in iterate_supers
* Struck through repros no longer work on HEAD.