INFO: task jbd2/sda1-8:2817 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D running task stack:26008 pid:2817 tgid:2817 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1325/0x47d0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 io_schedule+0x8a/0xf0 kernel/sched/core.c:8154 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:105 [inline] __wait_on_buffer+0x64/0x70 fs/buffer.c:118 wait_on_buffer include/linux/buffer_head.h:422 [inline] journal_wait_on_commit_record fs/jbd2/commit.c:170 [inline] jbd2_journal_commit_transaction+0x4837/0x6700 fs/jbd2/commit.c:907 kjournald2+0x200/0x760 fs/jbd2/journal.c:199 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/30: #0: ffffffff896e2b40 (rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] , at: rcu_read_lock include/linux/rcupdate.h:840 [inline] , at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by udevd/2857: 2 locks held by getty/2919: #0: ffff888114ad30a0 ( &tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452e8 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 6 locks held by kworker/1:3/5250: 3 locks held by kworker/1:6/5338: 5 locks held by kworker/u8:3/10622: #0: ffff888100e98940 ( (wq_completion)netns){+.+.}-{0:0} , at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90015a6fd18 ( net_cleanup_work ){+.+.}-{0:0} , at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff8ab0b6c8 ( pernet_ops_rwsem ){++++}-{4:4} , at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673 #3: ffffffff8ab24100 (rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 #4: ffffffff896ee5e8 ( rcu_state.exp_mutex){+.+.}-{4:4} , at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 4 locks held by kworker/1:8/14843: 2 locks held by kworker/u8:2/15463: 1 lock held by syz-executor/18638: #0: ffffffff8ab0b6c8 ( pernet_ops_rwsem){++++}-{4:4} , at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575 2 locks held by syz-executor/18649: 2 locks held by syz-executor/18654: #0: ffffffff8ab0b6c8 (pernet_ops_rwsem ){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575 #1: ffffffff896ee5e8 ( rcu_state.exp_mutex ){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/u8:5/18659: #0: ffff88810db3e940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90012a77d18 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff8ab24100 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ab24100 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4769 1 lock held by syz-executor/18666: 2 locks held by kworker/u8:6/18772: 2 locks held by kworker/u8:7/18775: 1 lock held by syz-executor/19131: #0: ffffffff8ab24100 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ab24100 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ab24100 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8bb/0x2210 net/core/rtnetlink.c:4158 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18529 Comm: syz.4.3226 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline] RIP: 0010:lock_release+0x65/0x310 kernel/locking/lockdep.c:5881 Code: 05 60 81 63 09 0f 82 02 02 00 00 44 8b 05 27 91 63 09 45 85 c0 0f 84 48 01 00 00 65 8b 05 83 82 6e 0b 85 c0 0f 85 39 01 00 00 <65> 4c 8b 25 7b 3f 6e 0b 41 8b bc 24 54 0b 00 00 85 ff 0f 85 21 01 RSP: 0018:ffffc90014f27558 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff896e2b40 RCX: ffffffff8b558c01 RDX: 0000000000000000 RSI: ffffffff87b15300 RDI: ffffffff8927abe8 RBP: ffffffff816f817e R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000000632d R12: ffffc90014f27660 R13: ffffc90014f27610 R14: ffffc90014f27ed0 R15: ffffc90014f27644 FS: 0000000000000000(0000) GS:ffff88826873a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f09f52580a0 CR3: 000000010b328000 CR4: 00000000003506f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_pages_prepare+0x558/0xcb0 mm/page_alloc.c:1451 __free_contig_range_common.constprop.0+0x12c/0x230 mm/page_alloc.c:6897 __free_contig_range mm/page_alloc.c:6942 [inline] free_pages_bulk+0x126/0x1f0 mm/page_alloc.c:5257 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3439 vfree mm/vmalloc.c:3488 [inline] vfree+0x107/0x750 mm/vmalloc.c:3462 kcov_put kernel/kcov.c:447 [inline] kcov_put kernel/kcov.c:443 [inline] kcov_close+0x34/0x60 kernel/kcov.c:554 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d2/0x2a50 kernel/exit.c:1009 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0xd2/0x530 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x682/0x7f0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff609dedb2b Code: Unable to access opcode bytes at 0x7ff609dedb01. RSP: 002b:00007ff608844f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007ff609dedb2b RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003 RBP: 00007ff608845fd0 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000200000000000 R14: 0000000000000000 R15: 0000000000000000