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INFO: task hung in __fdget_pos (2)

Status: closed as dup on 2018/10/27 13:29
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+abc28230a285d72e80d3@syzkaller.appspotmail.com
First crash: 2156d, last: 1928d
▶ ▼ Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
INFO: rcu detected stall in sys_creat exfat 98 1916d 2007d
▶ ▼ Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __fdget_pos kernfs 1 2216d 2216d 0/26 closed as invalid on 2018/03/27 11:08
android-44 INFO: task hung in __fdget_pos 2 2036d 2049d 0/2 auto-closed as invalid on 2019/03/21 05:21
linux-6.1 INFO: task hung in __fdget_pos 1 194d 194d 0/3 auto-obsoleted due to no activity on 2024/01/16 13:13
android-49 INFO: task hung in __fdget_pos 22 2037d 2168d 0/3 auto-closed as invalid on 2019/03/20 03:41
upstream INFO: task hung in __fdget_pos (4) fs syz error 86 2d12h 229d 0/26 upstream: reported syz repro on 2023/09/03 04:11
upstream INFO: task hung in __fdget_pos (3) fs 3 923d 940d 0/26 auto-closed as invalid on 2022/01/07 10:38
android-414 INFO: task hung in __fdget_pos 1 1905d 1836d 0/1 auto-closed as invalid on 2019/07/30 11:39
linux-5.15 INFO: task hung in __fdget_pos (2) 1 5d05h 5d05h 0/3 upstream: reported on 2024/04/14 16:46
linux-5.15 INFO: task hung in __fdget_pos 1 385d 385d 0/3 auto-obsoleted due to no activity on 2023/07/29 10:54

Sample crash report:
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
INFO: task syz-executor0:13126 blocked for more than 140 seconds.
      Not tainted 4.20.0+ #169
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
syz-executor0   D23608 13126   8164 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3472
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
 schedule+0xfe/0x460 kernel/sched/core.c:3516
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 __fdget_pos+0x1bb/0x200 fs/file.c:766
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 fdget_pos include/linux/file.h:70 [inline]
 ksys_write+0x7f/0x260 fs/read_write.c:593
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
__find_get_block_slow() failed. block=1, b_blocknr=8
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
device loop0 blocksize: 4096
RIP: 0033:0x4579b9
Code: Bad RIP value.
RSP: 002b:00007f3136d59c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004579b9
RDX: 00000000fffffd97 RSI: 0000000020000180 RDI: 0000000000000005
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3136d5a6d4
R13: 00000000004c6aa0 R14: 00000000004dbe38 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1028:
 #0: 00000000efde4872 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
1 lock held by rsyslogd/8040:
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 #0: 00000000a0d5ecde (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
2 locks held by getty/8130:
 #0: 00000000fc461ce2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000ca5b7641 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
2 locks held by getty/8131:
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 #0: 0000000015bcb384 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 #1: 00000000f8cbff4a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
2 locks held by getty/8132:
 #0: 00000000ce3c4da8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 #1: 000000005936f3dd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/8133:
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 #0: 000000006dbc3eb1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 #1: 000000005adaf0f2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/8134:
 #0: 000000006a57b992 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000bdf15f18 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/8135:
 #0: 0000000033ff82e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
__find_get_block_slow() failed. block=1, b_blocknr=8
 #1: 00000000dc7a0ad6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
b_state=0x00000029, b_size=512
2 locks held by getty/8136:
device loop0 blocksize: 4096
 #0: 00000000510deda8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 0000000078dbb994 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
3 locks held by kworker/u4:5/10578:
4 locks held by syz-executor0/13118:
1 lock held by syz-executor0/13126:
 #0: 000000007f8fb103 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096

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

NMI backtrace for cpu 0
CPU: 0 PID: 1028 Comm: khungtaskd Not tainted 4.20.0+ #169
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1c2/0x22c lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xb51/0x1060 kernel/hung_task.c:289
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.027 msecs
NMI backtrace for cpu 1
CPU: 1 PID: 512 Comm: kworker/u4:4 Not tainted 4.20.0+ #169
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x1/0x280 lib/smp_processor_id.c:12
Code: ff ff ff e8 61 8a 32 fe e9 ac ec ff ff 48 8b bd 18 ff ff ff e8 f0 8a 32 fe e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 55 <48> 89 e5 41 57 41 56 49 89 f6 41 55 49 89 fd 41 54 53 48 83 ec 08
RSP: 0018:ffff8880a93b73c0 EFLAGS: 00000293
RAX: ffff8880a88c25c0 RBX: 1ffff11015276e7d RCX: ffffffff87bff1cd
RDX: 0000000000000000 RSI: ffffffff8880d9e0 RDI: ffffffff8880da20
RBP: ffff8880a93b73d0 R08: ffff8880a88c25c0 R09: 0000000000000008
R10: 0000000000000050 R11: ffff8880a88c25c0 R12: 000000000002dbc0
R13: ffff8880a93b7448 R14: dffffc0000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 0000000096142000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_dynticks_curr_cpu_in_eqs+0x69/0x170 kernel/rcu/tree.c:290
 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:906
 rcu_read_lock include/linux/rcupdate.h:608 [inline]
 batadv_nc_process_nc_paths.part.16+0x41d/0x540 net/batman-adv/network-coding.c:698
 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:690 [inline]
 batadv_nc_worker+0x6d4/0x920 net/batman-adv/network-coding.c:739
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
__find_get_block_slow() failed. block=1, b_blocknr=8

Crashes (36):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/12/27 00:30 upstream eed9688f8513 e747ec98 .config console log report ci-upstream-kasan-gce-smack-root
2018/11/27 07:30 upstream 6f8b52ba442c ac912200 .config console log report ci-upstream-kasan-gce-smack-root
2018/10/20 07:19 upstream c7b70a641df2 ecb386fe .config console log report ci-upstream-kasan-gce-root
2018/10/12 05:43 upstream 0778a9f2dd92 ba6ddb43 .config console log report ci-upstream-kasan-gce-root
2018/10/11 03:05 upstream b8db9e69dba9 5f818b4b .config console log report ci-upstream-kasan-gce-smack-root
2018/10/10 03:50 upstream 64c5e530ac2c 8b311eaf .config console log report ci-upstream-kasan-gce-smack-root
2018/10/09 09:37 upstream 64c5e530ac2c 8b311eaf .config console log report ci-upstream-kasan-gce-smack-root
2018/10/08 22:15 upstream 0854ba5ff5c9 8b311eaf .config console log report ci-upstream-kasan-gce-root
2018/10/07 05:03 upstream c1d84a1b42ef 8b311eaf .config console log report ci-upstream-kasan-gce-selinux-root
2018/10/05 14:24 upstream befad944e231 8b311eaf .config console log report ci-upstream-kasan-gce-root
2018/10/01 04:04 upstream 17b57b1883c1 41e4b329 .config console log report ci-upstream-kasan-gce-root
2018/10/01 02:35 upstream 17b57b1883c1 41e4b329 .config console log report ci-upstream-kasan-gce-root
2018/10/01 01:59 upstream 17b57b1883c1 41e4b329 .config console log report ci-upstream-kasan-gce-root
2018/09/25 11:32 upstream 2dd68cc7fd8c 0e7547d7 .config console log report ci-upstream-kasan-gce-root
2018/09/23 04:11 upstream 10dc890d4228 37079712 .config console log report ci-upstream-kasan-gce-smack-root
2018/09/08 00:36 upstream a49a9dcce802 69cfeb80 .config console log report ci-upstream-kasan-gce-smack-root
2018/09/01 11:13 upstream 420f51f4ab6b a4718693 .config console log report ci-upstream-kasan-gce-root
2018/08/19 01:50 upstream a18d783fedfe de20bcbb .config console log report ci-upstream-kasan-gce-root
2018/08/15 03:43 upstream d0055f351e64 0e6dcb88 .config console log report ci-upstream-kasan-gce-root
2018/08/12 13:36 upstream ec0c96714e7d 7a88b141 .config console log report ci-upstream-kasan-gce-root
2018/08/09 01:35 upstream fedb8da96355 2eeda842 .config console log report ci-upstream-kasan-gce-root
2018/08/07 13:41 upstream 1236568ee3cb 1beb8136 .config console log report ci-upstream-kasan-gce-root
2018/08/06 01:54 upstream a8c199208cd6 1beb8136 .config console log report ci-upstream-kasan-gce-root
2018/08/02 14:37 upstream 6b4703768268 0a7cf4ec .config console log report ci-upstream-kasan-gce-root
2018/07/17 16:29 upstream 30b06abfb92b 6d5bd5b5 .config console log report ci-upstream-kasan-gce-root
2018/06/14 11:05 upstream 2837461dbe6f 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/14 05:03 upstream be779f03d563 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/06 12:27 upstream af6c5d5e01ad 41f9540d .config console log report ci-upstream-kasan-gce-root
2018/05/31 08:05 upstream 88a867653065 2f93b54f .config console log report ci-upstream-kasan-gce-root
2018/05/26 23:21 upstream bc2dbc5420e8 f48c20b8 .config console log report ci-upstream-kasan-gce-root
2018/05/26 10:28 upstream 62d18ecfa641 f48c20b8 .config console log report ci-upstream-kasan-gce-root
2018/05/25 02:10 upstream d883c6cf3b39 f48c20b8 .config console log report ci-upstream-kasan-gce-root
2019/01/08 04:39 linux-next 139287cc2cc0 69d69aa9 .config console log report ci-upstream-linux-next-kasan-gce-root
2018/11/29 15:01 linux-next 442b8cea2477 4b6d14f2 .config console log report ci-upstream-linux-next-kasan-gce-root
2018/08/29 16:16 linux-next 87b93b43da14 53ff8784 .config console log report ci-upstream-linux-next-kasan-gce-root
2018/08/04 18:55 linux-next 116b181bb646 3476a2df .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.