INFO: task syz.4.21:4629 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.21 state:D stack:22304 pid:4629 ppid:4422 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1e8/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4c6/0xfa0 fs/jfs/jfs_metapage.c:639 xtSplitPage+0x238/0x1c10 fs/jfs/jfs_xtree.c:974 xtSplitUp+0x293/0x1c20 fs/jfs/jfs_xtree.c:771 xtInsert+0x455/0xbb0 fs/jfs/jfs_xtree.c:593 extAlloc+0x9f6/0xf30 fs/jfs/jfs_extent.c:145 jfs_get_block+0x343/0xab0 fs/jfs/inode.c:254 __block_write_begin_int+0x54b/0x1a70 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:310 generic_perform_write+0x2f7/0x5a0 mm/filemap.c:3862 __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x3ea/0x7f0 fs/coredump.c:977 elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fcc3598f751 RSP: 002b:00000000fffffe60 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fcc35be5fa0 RCX: 00007fcc3598f749 RDX: 0000000000000000 RSI: 00000000fffffe60 RDI: 0000000000040000 RBP: 00007fcc35a13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fcc35be6038 R14: 00007fcc35be5fa0 R15: 00007ffe8284d748 Showing all locks held in the system: 5 locks held by kworker/u4:0/9: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900000e7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11489 #4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 3 locks held by kworker/u4:1/11: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by kworker/u4:3/46: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b77d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 3 locks held by kworker/1:2/128: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90002d87d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104 2 locks held by getty/4029: #0: ffff88814d47d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by kworker/1:4/4362: #0: ffff88814d1ad938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003f37d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 2 locks held by kworker/0:6/4474: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900035a7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/0:10/4479: #0: ffff88814d1ad938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003637d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 4 locks held by syz.4.21/4629: #0: ffff8880249d0460 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x15de/0x22b0 fs/coredump.c:823 #1: ffff88806af9bd00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88806af9bd00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986 #2: ffff88806af9b8b8 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x13e/0xab0 fs/jfs/inode.c:219 #3: ffff88806af9b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10b/0xf30 fs/jfs/jfs_extent.c:81 4 locks held by syz.5.105/6116: #0: ffff88801b29a460 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x15de/0x22b0 fs/coredump.c:823 #1: ffff88806af98ec0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88806af98ec0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986 #2: ffff88806af98a78 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x13e/0xab0 fs/jfs/inode.c:219 #3: ffff88806af98b08 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10b/0xf30 fs/jfs/jfs_extent.c:81 2 locks held by syz-executor/6627: #0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5b/0x930 net/wireless/nl80211.c:16235 1 lock held by syz-executor/6645: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 4 locks held by syz-executor/6654: #0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffff88805b406698 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 #2: ffff88805f3da2f8 (&devlink->lock_key#35){+.+.}-{3:3}, at: devl_lock net/devlink/leftover.c:275 [inline] #2: ffff88805f3da2f8 (&devlink->lock_key#35){+.+.}-{3:3}, at: devlink_nl_cmd_port_get_dumpit+0x16e/0x560 net/devlink/leftover.c:1537 #3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: devlink_nl_port_fill+0x298/0x910 net/devlink/leftover.c:1276 7 locks held by syz-executor/6720: #0: ffff888044c92460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff88807d664488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff888026ef2da0 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888026ef2da0 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d44d168 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209 #4: ffff888077dff0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #4: ffff888077dff0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline] #4: ffff888077dff0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283 #5: ffff888077dfc2f8 (&devlink->lock_key#27){+.+.}-{3:3}, at: nsim_drv_remove+0x54/0x160 drivers/net/netdevsim/dev.c:1677 #6: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381 1 lock held by syz.4.231/6890: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3626 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_switch+0x51/0xe0 kernel/kcov.c:348 Code: 48 85 c0 0f 84 a7 00 00 00 41 57 41 56 41 54 53 48 8b 0c cd 78 1a 70 8a 48 8b 54 24 20 65 4c 8b 05 c4 8a 81 7e 45 31 c9 eb 08 <49> ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d b2 8a 81 7e 41 RSP: 0018:ffffc90003267788 EFLAGS: 00000293 RAX: 0000000000000002 RBX: dffffc0000000000 RCX: 0000000000000001 RDX: ffffffff8a018e4b RSI: ffffffff8de829e0 RDI: 0000000000000025 RBP: ffffffff8a6ccd01 R08: ffff88807c8b0000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8a6ccd01 R13: 0000000000000000 R14: ffffffff8a6ccd01 R15: 0000000000000025 FS: 00007f7185655c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000fffffc80 CR3: 0000000018354000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: format_decode+0x13b/0x1330 lib/vsprintf.c:2539 vsnprintf+0xef/0x1a00 lib/vsprintf.c:2757 sprintf+0xd6/0x120 lib/vsprintf.c:3009 print_syslog kernel/printk/printk.c:1267 [inline] info_print_prefix+0xd3/0x300 kernel/printk/printk.c:1297 record_print_text+0x151/0x420 kernel/printk/printk.c:1349 syslog_print+0x366/0x590 kernel/printk/printk.c:1560 do_syslog+0x7bd/0x8b0 kernel/printk/printk.c:1679 __do_sys_syslog kernel/printk/printk.c:1771 [inline] __se_sys_syslog kernel/printk/printk.c:1769 [inline] __x64_sys_syslog+0x78/0x90 kernel/printk/printk.c:1769 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f718581fa37 Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007fffba52ffc8 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f71859bf490 RCX: 00007f718581fa37 RDX: 00000000000003ff RSI: 00007f71859bf490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f71859bf490 R13: 00007f718599cdfe R14: 00007f71859bf50e R15: 00007f71859bf50e