syzbot


INFO: task hung in fuse_simple_request (2)

Status: upstream: reported on 2024/06/24 00:58
Reported-by: syzbot+d3dc6bb0d428fdb76862@syzkaller.appspotmail.com
First crash: 108d, last: 57d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in fuse_simple_request 12 350d 448d 0/3 auto-obsoleted due to no activity on 2024/02/03 13:59
upstream INFO: task hung in fuse_simple_request fuse C inconclusive error 273 17d 1396d 0/28 upstream: reported C repro on 2020/12/13 21:13
linux-6.1 INFO: task hung in fuse_simple_request 6 327d 415d 0/3 auto-obsoleted due to no activity on 2024/02/26 14:29
linux-6.1 INFO: task hung in fuse_simple_request (2) 2 12d 110d 0/3 upstream: reported on 2024/06/21 20:45
upstream INFO: task can't die in request_wait_answer fuse C error 14 967d 1478d 0/28 auto-obsoleted due to no activity on 2023/04/16 22:02

Sample crash report:
INFO: task syz.2.927:7135 blocked for more than 145 seconds.
      Not tainted 5.15.164-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.927       state:D stack:23168 pid: 7135 ppid:  6682 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 request_wait_answer fs/fuse/dev.c:411 [inline]
 __fuse_request_send fs/fuse/dev.c:430 [inline]
 fuse_simple_request+0x112f/0x1a00 fs/fuse/dev.c:515
 fuse_flush+0x5d2/0x800 fs/fuse/file.c:517
 filp_close+0xad/0x150 fs/open.c:1361
 __range_close fs/file.c:712 [inline]
 __close_range+0x15c/0x780 fs/file.c:779
 __do_sys_close_range fs/open.c:1406 [inline]
 __se_sys_close_range fs/open.c:1403 [inline]
 __x64_sys_close_range+0x76/0x80 fs/open.c:1403
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9087b8b9f9
RSP: 002b:00007fffb0100a88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 0000000000039538 RCX: 00007f9087b8b9f9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fffb0100b60 R08: 0000000000000001 R09: 00007fffb0100d6f
R10: 00007f9087a12000 R11: 0000000000000246 R12: 0000000000000032
R13: 00007fffb0100b80 R14: 00007fffb0100ba0 R15: ffffffffffffffff
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/1:0/21:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90000db7d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
 #0: ffff888011dd5138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000155fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8da24d10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:561
 #3: ffffffff8c923ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
2 locks held by getty/3325:
 #0: ffff88807e478098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:7/3616:
3 locks held by kworker/0:9/3718:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900030d7d20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
3 locks held by kworker/1:13/5944:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002e97d20 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff888051074400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xab0 drivers/net/netdevsim/dev.c:757
3 locks held by kworker/1:17/5950:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003057d20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff888051071240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1478
1 lock held by syz-executor/6384:
 #0: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0xa4f/0xc40 net/core/dev.c:10656
1 lock held by syz-executor/7163:
 #0: ffffffff8c923ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
7 locks held by syz-executor/7353:
 #0: ffff88807e5a2460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #1: ffff888062767088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
 #2: ffff88801e5aa3a8 (kn->active#232){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20b/0x4f0 fs/kernfs/file.c:288
 #3: ffffffff8d372948 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xf1/0x470 drivers/net/netdevsim/bus.c:344
 #4: ffff888077893178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #4: ffff888077893178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
 #4: ffff888077893178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xc2/0x7f0 drivers/base/dd.c:1259
 #5: ffff888051074400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
 #5: ffff888051074400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x118/0x240 drivers/net/netdevsim/dev.c:1561
 #6: ffffffff8c923ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
4 locks held by syz-executor/7354:
 #0: ffff88807e5a2460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #1: ffff888077e7d888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
 #2: ffff88801e5aa3a8 (kn->active#232){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20b/0x4f0 fs/kernfs/file.c:288
 #3: ffffffff8d372948 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xf1/0x470 drivers/net/netdevsim/bus.c:344
1 lock held by syz.4.1029/7466:
 #0: ffffffff8c923ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
1 lock held by syz-executor/7501:
 #0: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
2 locks held by syz-executor/7503:
1 lock held by syz-executor/7515:
 #0: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626
1 lock held by syz.0.1045/7537:
 #0: ffffffff8c923ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
1 lock held by syz-executor/7546:
 #0: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #0: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor/7552:
 #0: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8da308c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7503 Comm: syz-executor Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:lock_acquire+0x275/0x4f0 kernel/locking/lockdep.c:5627
Code: 44 24 40 0e 36 e0 45 4b c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 11 00 00 00 00 66 43 c7 44 25 15 00 00 <43> c6 44 25 17 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24 00 01 00
RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 1ffff920001ba174 RCX: ffffffff816365a2
RDX: dffffc0000000000 RSI: ffffffff8a8b3ca0 RDI: ffffffff8ad8f800
RBP: ffffc90000dd0c98 R08: dffffc0000000000 R09: fffffbfff1f8e05e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001ba170
R13: dffffc0000000000 R14: ffffc90000dd0ba0 R15: 0000000000000046
FS:  00005555566c9500(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560a993f6058 CR3: 0000000051858000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 advance_sched+0x47/0x940 net/sched/sch_taprio.c:716
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:console_unlock+0xe53/0x12b0 kernel/printk/printk.c:2749
Code: 00 48 83 7c 24 18 00 75 19 e8 f9 04 1a 00 eb 18 e8 f2 04 1a 00 e8 fd b0 cc 08 48 83 7c 24 18 00 74 e7 e8 e0 04 1a 00 fb 31 ff <44> 89 f6 e8 35 08 1a 00 31 db 45 85 f6 0f 95 c0 89 c1 0a 4c 24 17
RSP: 0018:ffffc90002d66540 EFLAGS: 00000246
RAX: ffffffff81665c80 RBX: 0000000000000000 RCX: ffff88801e5f5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002d667d0 R08: ffffffff81665c4b R09: fffffbfff1f8e019
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1a4c44e
R13: ffffffff8d2622a8 R14: 0000000000000000 R15: dffffc0000000000
 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
 _printk+0xd1/0x120 kernel/printk/printk.c:2299
 br_set_state+0x35b/0x610 net/bridge/br_stp.c:51
 new_nbp+0x4a7/0x640 net/bridge/br_if.c:434
 br_add_if+0x3a2/0x1200 net/bridge/br_if.c:610
 do_set_master net/core/rtnetlink.c:2543 [inline]
 do_setlink+0xe71/0x3b00 net/core/rtnetlink.c:2748
 __rtnl_newlink net/core/rtnetlink.c:3429 [inline]
 rtnl_newlink+0x17a4/0x2070 net/core/rtnetlink.c:3549
 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5629
 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2504
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x564/0x720 net/socket.c:2058
 __do_sys_sendto net/socket.c:2070 [inline]
 __se_sys_sendto net/socket.c:2066 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2066
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f19e030578c
Code: 2a 5a 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5a 02 00 48 8b
RSP: 002b:00007ffeea70eb70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f19e0fce620 RCX: 00007f19e030578c
RDX: 0000000000000028 RSI: 00007f19e0fce670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffeea70ebc4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f19e0fce670 R15: 0000000000000000
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/14 05:46 linux-5.15.y 7e89efd3ae1c bde81f6f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
2024/06/24 00:58 linux-5.15.y 4878aadf2d15 edc5149a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in fuse_simple_request
* Struck through repros no longer work on HEAD.