INFO: task syz.1.22:6110 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.22 state:D stack:28568 pid:6110 tgid:6108 ppid:5947 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 __mutex_lock_common kernel/locking/mutex.c:686 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:770 seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 seq_read+0x369/0x480 fs/seq_file.c:162 do_loop_readv_writev fs/read_write.c:847 [inline] vfs_readv+0x5aa/0x850 fs/read_write.c:1020 do_preadv fs/read_write.c:1132 [inline] __do_sys_preadv fs/read_write.c:1179 [inline] __se_sys_preadv fs/read_write.c:1174 [inline] __x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174 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: 0033:0x7f068378f749 RSP: 002b:00007f06846af038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f06839e6090 RCX: 00007f068378f749 RDX: 0000000000000001 RSI: 00002000000005c0 RDI: 0000000000000004 RBP: 00007f0683813f91 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f06839e6128 R14: 00007f06839e6090 R15: 00007fff64457eb8 INFO: task syz.2.37:6190 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.37 state:D stack:28568 pid:6190 tgid:6188 ppid:5950 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 __mutex_lock_common kernel/locking/mutex.c:686 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:770 seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 seq_read+0x369/0x480 fs/seq_file.c:162 do_loop_readv_writev fs/read_write.c:847 [inline] vfs_readv+0x5aa/0x850 fs/read_write.c:1020 do_preadv fs/read_write.c:1132 [inline] __do_sys_preadv fs/read_write.c:1179 [inline] __se_sys_preadv fs/read_write.c:1174 [inline] __x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174 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: 0033:0x7fe8e338f749 RSP: 002b:00007fe8e4250038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fe8e35e6090 RCX: 00007fe8e338f749 RDX: 0000000000000001 RSI: 00002000000005c0 RDI: 0000000000000004 RBP: 00007fe8e3413f91 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe8e35e6128 R14: 00007fe8e35e6090 R15: 00007ffcdac37898 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: 1 lock held by khungtaskd/31: #0: ffffffff8df3d820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff8880301e20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz.1.22/6109: 1 lock held by syz.1.22/6110: #0: ffff88806a07ad58 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.2.37/6189: 1 lock held by syz.2.37/6190: #0: ffff8880310702f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.4.48/6272: 1 lock held by syz.4.48/6274: #0: ffff88807f09cd58 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.3.52/6298: 1 lock held by syz.3.52/6299: #0: ffff88807f24f790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.0.54/6320: 1 lock held by syz.0.54/6322: #0: ffff888030fa7668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.6.50/6338: 1 lock held by syz.6.50/6339: #0: ffff88802f4eab08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.5.56/6346: 1 lock held by syz.5.56/6347: #0: ffff88802f4ea9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.7.57/6438: 1 lock held by syz.7.57/6440: #0: ffff88802f4ea668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 1 lock held by syz.9.59/6493: 1 lock held by syz.9.59/6494: #0: ffff888077bdbc30 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.8.63/6503: 1 lock held by syz.8.63/6506: #0: ffff88802fcb41c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.2.61/6513: 1 lock held by syz.2.61/6517: #0: ffff88807f09c790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.1.64/6537: 2 locks held by syz.4.62/6568: 1 lock held by syz.4.62/6569: #0: ffff8880286b59e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.3.65/6687: 1 lock held by syz.3.65/6689: #0: ffff888030fa7790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.6.67/6700: 1 lock held by syz.6.67/6701: #0: ffff88807743e0a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.0.66/6699: 1 lock held by syz.0.66/6703: #0: ffff88807743e1c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.5.68/6707: 1 lock held by syz.5.68/6708: #0: ffff88802fcb40a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 2 locks held by syz.7.69/6712: 1 lock held by syz.7.69/6713: #0: ffff88802fcb4668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 9 locks held by syz-executor/6719: #0: ffff888033e4e420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888033e4e420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682 #1: ffff8880404c3488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343 #2: ffff888141fcf3c8 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888141fcf3c8 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344 #3: ffffffff8eb71308 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff88805bb400e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805bb400e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff88805bb400e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff8880202d3250 (&devlink->lock_key#11){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1777 #6: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175 #7: ffff8880329ecd48 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2773 [inline] #7: ffff8880329ecd48 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x58b/0x2340 net/core/dev.c:12352 #8: ffffffff8df432f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #8: ffffffff8df432f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956 2 locks held by syz-executor/6731: #0: ffffffff8f7e22d8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7e22d8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f7e22d8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by syz-executor/6734: #0: ffffffff8f7e1730 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7e1730 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f7e1730 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 4 locks held by kworker/u8:45/6739: #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b86260d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117 #3: ffffffff99ac5768 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x87/0x540 lib/debugobjects.c:818 2 locks held by syz-executor/6743: #0: ffffffff8f2ce4f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11497 2 locks held by syz-executor/6749: #0: ffffffff8f2ce4f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f2dba08 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1146 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6346 Comm: syz.5.56 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314 Code: 48 89 44 11 20 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 50 79 92 65 8b 0d 58 ab b7 10 81 e1 00 01 ff 00 RSP: 0018:ffffc90004c2f538 EFLAGS: 00000206 RAX: ffffffff8b53f66b RBX: 0000000000000010 RCX: ffff88807a2d3d00 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 000000000000000a RBP: ffffc90004c2f660 R08: ffffc90004c2f5d7 R09: 0000000000000000 R10: ffffc90004c2f5c0 R11: fffff52000985ebb R12: 000000003b9a64b9 R13: 000000003b9a64b9 R14: ffffc9001a2bb8aa R15: 00ffffffffffff10 FS: 00007fa6aa9856c0(0000) GS:ffff888125e8b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f48c77556e8 CR3: 0000000025c92000 CR4: 00000000003526f0 Call Trace: number+0x2db/0xf60 lib/vsprintf.c:508 vsnprintf+0x8e2/0xee0 lib/vsprintf.c:2910 seq_vprintf fs/seq_file.c:391 [inline] seq_printf+0x178/0x270 fs/seq_file.c:406 __io_uring_show_fdinfo io_uring/fdinfo.c:158 [inline] io_uring_show_fdinfo+0x9e4/0x18a0 io_uring/fdinfo.c:261 seq_show+0x5ac/0x710 fs/proc/fd.c:68 traverse+0x1ee/0x580 fs/seq_file.c:111 seq_read_iter+0xd08/0xe20 fs/seq_file.c:195 seq_read+0x369/0x480 fs/seq_file.c:162 do_loop_readv_writev fs/read_write.c:847 [inline] vfs_readv+0x5aa/0x850 fs/read_write.c:1020 do_preadv fs/read_write.c:1132 [inline] __do_sys_preadv fs/read_write.c:1179 [inline] __se_sys_preadv fs/read_write.c:1174 [inline] __x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174 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: 0033:0x7fa6a9b8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa6aa985038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fa6a9de5fa0 RCX: 00007fa6a9b8f749 RDX: 0000000000000001 RSI: 00002000000005c0 RDI: 0000000000000004 RBP: 00007fa6a9c13f91 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa6a9de6038 R14: 00007fa6a9de5fa0 R15: 00007ffddfa99f78