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INFO: task hung in __fuse_request_send

Status: upstream: reported C repro on 2019/05/02 04:17
Reported-by: syzbot+540f7599aabee42b9f52@syzkaller.appspotmail.com
First crash: 2060d, last: 1074d
Fix bisection the fix commit could be any of (bisect log):
  bc2bccef19ee Linux 4.14.130
  4139fb08c05f Linux 4.14.187
   
▶ ▼ Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __fuse_request_send (3) fuse 25 772d 844d 0/28 auto-obsoleted due to no activity on 2023/02/11 11:55
upstream INFO: task hung in __fuse_request_send (2) fuse 8 2072d 2120d 0/28 auto-closed as invalid on 2019/10/18 14:12
upstream INFO: task hung in __fuse_request_send fuse C 1746 2134d 2354d 0/28 closed as invalid on 2019/02/22 11:41
linux-4.19 INFO: task hung in __fuse_request_send C error 77 723d 2013d 0/1 upstream: reported C repro on 2019/06/18 06:08
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2023/02/08 23:32 9m retest repro linux-4.14.y report log
2022/09/18 17:29 12m retest repro linux-4.14.y report log
▶ ▼ Fix bisection attempts (7)
Created Duration User Patch Repo Result
2020/06/26 21:33 34m (3) bisect fix linux-4.14.y OK (2) job log
2020/05/26 23:38 32m bisect fix linux-4.14.y OK (0) job log log
2020/04/26 23:06 32m bisect fix linux-4.14.y OK (0) job log log
2020/03/27 22:34 31m bisect fix linux-4.14.y OK (0) job log log
2020/02/26 22:01 33m bisect fix linux-4.14.y OK (0) job log log
2020/01/27 21:28 32m bisect fix linux-4.14.y OK (0) job log log
2019/12/01 08:18 31m bisect fix linux-4.14.y OK (0) job log log

Sample crash report:
audit: type=1400 audit(1561539902.623:36): avc:  denied  { map } for  pid=7032 comm="syz-executor358" path="/root/syz-executor358861599" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
INFO: task syz-executor358:7033 blocked for more than 140 seconds.
      Not tainted 4.14.130 #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor358 D27664  7033   7030 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 request_wait_answer+0x33e/0x650 fs/fuse/dev.c:478
 __fuse_request_send+0x10d/0x1b0 fs/fuse/dev.c:498
 fuse_request_send+0x63/0x70 fs/fuse/dev.c:511
 fuse_simple_request+0x2c4/0x650 fs/fuse/dev.c:569
 fuse_lookup_name+0x248/0x610 fs/fuse/dir.c:323
 fuse_lookup+0xdd/0x380 fs/fuse/dir.c:361
 lookup_slow+0x226/0x440 fs/namei.c:1695
 walk_component+0x698/0x1d00 fs/namei.c:1824
 lookup_last fs/namei.c:2292 [inline]
 path_lookupat.isra.0+0x1bb/0x7b0 fs/namei.c:2342
 filename_lookup+0x18e/0x380 fs/namei.c:2376
 user_path_at_empty+0x43/0x50 fs/namei.c:2630
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0xcd/0x160 fs/stat.c:185
 vfs_stat include/linux/fs.h:3058 [inline]
 SYSC_newstat+0x95/0x100 fs/stat.c:337
 SyS_newstat+0x1e/0x30 fs/stat.c:333
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x445b99
RSP: 002b:00007f4970a28db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445b99
RDX: 0000000000000031 RSI: 0000000000000000 RDI: 0000000020000580
RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c
R13: 00007ffec93c4faf R14: 00007f4970a299c0 R15: 20c49ba5e353f7cf
INFO: task syz-executor358:7034 blocked for more than 140 seconds.
      Not tainted 4.14.130 #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor358 D29360  7034   7030 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
 rwsem_down_write_failed+0x5ce/0xb50 kernel/locking/rwsem-xadd.c:617
 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x53/0x90 kernel/locking/rwsem.c:56
 inode_lock include/linux/fs.h:718 [inline]
 lock_mount+0x8c/0x2c0 fs/namespace.c:2119
 do_add_mount+0x27/0x350 fs/namespace.c:2496
 do_new_mount fs/namespace.c:2563 [inline]
 do_mount+0x1307/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x445b99
RSP: 002b:00007f4970a07db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000445b99
RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000000000000
RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 00000000006dac3c
R13: 00007ffec93c4faf R14: 00007f4970a089c0 R15: 20c49ba5e353f7cf
INFO: task syz-executor358:7035 blocked for more than 140 seconds.
      Not tainted 4.14.130 #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor358 D28904  7035   7030 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
 rwsem_down_write_failed+0x5ce/0xb50 kernel/locking/rwsem-xadd.c:617
 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x53/0x90 kernel/locking/rwsem.c:56
 inode_lock include/linux/fs.h:718 [inline]
 fuse_reverse_inval_entry+0x97/0x600 fs/fuse/dir.c:962
 fuse_notify_delete fs/fuse/dev.c:1562 [inline]
 fuse_notify fs/fuse/dev.c:1796 [inline]
 fuse_dev_do_write+0xb3d/0x2120 fs/fuse/dev.c:1871
 fuse_dev_write+0x12e/0x1b0 fs/fuse/dev.c:1955
 call_write_iter include/linux/fs.h:1777 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x4a7/0x6b0 fs/read_write.c:482
 vfs_write+0x198/0x500 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xfd/0x230 fs/read_write.c:582
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x445b99
RSP: 002b:00007f49709e6db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000006dac48 RCX: 0000000000445b99
RDX: 000000000000002e RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000006dac40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac4c
R13: 00007ffec93c4faf R14: 00007f49709e79c0 R15: 20c49ba5e353f7cf
INFO: task syz-executor358:7037 blocked for more than 140 seconds.
      Not tainted 4.14.130 #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor358 D28496  7037   7030 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
 rwsem_down_write_failed+0x5ce/0xb50 kernel/locking/rwsem-xadd.c:617
 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x53/0x90 kernel/locking/rwsem.c:56
 inode_lock include/linux/fs.h:718 [inline]
 lock_mount+0x8c/0x2c0 fs/namespace.c:2119
 do_add_mount+0x27/0x350 fs/namespace.c:2496
 do_new_mount fs/namespace.c:2563 [inline]
 do_mount+0x1307/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x445b99
RSP: 002b:00007f49709a4db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000006dac68 RCX: 0000000000445b99
RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 00000000006dac60 R08: 0000000020000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac6c
R13: 00007ffec93c4faf R14: 00007f49709a59c0 R15: 20c49ba5e353f7cf
INFO: task syz-executor358:7038 blocked for more than 140 seconds.
      Not tainted 4.14.130 #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor358 D29184  7038   7030 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x1f6/0x390 kernel/locking/rwsem-xadd.c:309
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:66 [inline]
 down_read+0x49/0xb0 kernel/locking/rwsem.c:26
 inode_lock_shared include/linux/fs.h:728 [inline]
 lookup_slow+0x138/0x440 fs/namei.c:1673
 walk_component+0x698/0x1d00 fs/namei.c:1824
 lookup_last fs/namei.c:2292 [inline]
 path_lookupat.isra.0+0x1bb/0x7b0 fs/namei.c:2342
 filename_lookup+0x18e/0x380 fs/namei.c:2376
 user_path_at_empty+0x43/0x50 fs/namei.c:2630
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0xcd/0x160 fs/stat.c:185
 vfs_stat include/linux/fs.h:3058 [inline]
 SYSC_newstat+0x95/0x100 fs/stat.c:337
 SyS_newstat+0x1e/0x30 fs/stat.c:333
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x445b99
RSP: 002b:00007f4970983db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 00000000006dac78 RCX: 0000000000445b99
RDX: 0000000000000031 RSI: 0000000000000000 RDI: 0000000020000580
RBP: 00000000006dac70 R08: 00007f4970984700 R09: 0000000000000000
R10: 00007f4970984700 R11: 0000000000000246 R12: 00000000006dac7c
R13: 00007ffec93c4faf R14: 00007f49709849c0 R15: 20c49ba5e353f7cf

Showing all locks held in the system:
1 lock held by khungtaskd/1008:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff81483348>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4541
2 locks held by getty/7007:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7008:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7009:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7010:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7011:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7012:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7013:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff861a5c53>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83106146>] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by syz-executor358/7033:
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff818f79c8>] inode_lock_shared include/linux/fs.h:728 [inline]
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff818f79c8>] lookup_slow+0x138/0x440 fs/namei.c:1673
 #1:  (&fi->mutex){+.+.}, at: [<ffffffff8219944c>] fuse_lock_inode+0xbc/0xf0 fs/fuse/inode.c:365
1 lock held by syz-executor358/7034:
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff819495ec>] inode_lock include/linux/fs.h:718 [inline]
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff819495ec>] lock_mount+0x8c/0x2c0 fs/namespace.c:2119
2 locks held by syz-executor358/7035:
 #0:  (&fc->killsb){.+.+}, at: [<ffffffff82170f19>] fuse_notify_delete fs/fuse/dev.c:1559 [inline]
 #0:  (&fc->killsb){.+.+}, at: [<ffffffff82170f19>] fuse_notify fs/fuse/dev.c:1796 [inline]
 #0:  (&fc->killsb){.+.+}, at: [<ffffffff82170f19>] fuse_dev_do_write+0x1b59/0x2120 fs/fuse/dev.c:1871
 #1:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff8217ba97>] inode_lock include/linux/fs.h:718 [inline]
 #1:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff8217ba97>] fuse_reverse_inval_entry+0x97/0x600 fs/fuse/dir.c:962
1 lock held by syz-executor358/7037:
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff819495ec>] inode_lock include/linux/fs.h:718 [inline]
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff819495ec>] lock_mount+0x8c/0x2c0 fs/namespace.c:2119
1 lock held by syz-executor358/7038:
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff818f79c8>] inode_lock_shared include/linux/fs.h:728 [inline]
 #0:  (&type->i_mutex_dir_key#6){++++}, at: [<ffffffff818f79c8>] lookup_slow+0x138/0x440 fs/namei.c:1673

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

NMI backtrace for cpu 1
CPU: 1 PID: 1008 Comm: khungtaskd Not tainted 4.14.130 #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e7/0xb90 kernel/hung_task.c:274
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff861a673e

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/06/26 09:11 linux-4.14.y bc2bccef19ee 0a8d1a96 .config console log report syz C ci2-linux-4-14
2022/01/12 21:01 linux-4.14.y 4ba8e26127c3 44d1319a .config console log report info ci2-linux-4-14 INFO: task hung in __fuse_request_send
2021/12/07 10:47 linux-4.14.y 66722c42ec91 0230ba3e .config console log report info ci2-linux-4-14 INFO: task hung in __fuse_request_send
2021/03/27 04:33 linux-4.14.y 670d6552eda8 a8529b82 .config console log report info ci2-linux-4-14 INFO: task hung in __fuse_request_send
2021/03/21 15:45 linux-4.14.y cb83ddcd5332 4c9a64da .config console log report info ci2-linux-4-14 INFO: task hung in __fuse_request_send
2020/11/25 10:10 linux-4.14.y 87335852c5d9 1a1f4bd8 .config console log report info ci2-linux-4-14
2020/09/30 19:07 linux-4.14.y cbfa1702aaf6 a9767fb2 .config console log report info ci2-linux-4-14
2020/08/25 14:57 linux-4.14.y 6a24ca2506d6 344da168 .config console log report ci2-linux-4-14
2020/05/27 21:33 linux-4.14.y 4f68020fef1c 9072c126 .config console log report ci2-linux-4-14
2019/12/28 21:28 linux-4.14.y e1f7d50ae3a3 af6b8ef8 .config console log report ci2-linux-4-14
2019/05/02 03:16 linux-4.14.y fa5941f45d7e 7516d9fa .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.