INFO: task syz-executor:19192 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22544 pid:19192 tgid:19192 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821 lmLogClose+0xad/0x530 fs/jfs/jfs_logmgr.c:1441 jfs_umount+0x2da/0x3b0 fs/jfs/jfs_umount.c:124 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647 kill_block_super+0x44/0x90 fs/super.c:1671 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 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+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f047c59f317 RSP: 002b:00007fffc223ad18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f047c634474 RCX: 00007f047c59f317 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffc223add0 RBP: 00007fffc223add0 R08: 00007fffc223bdd0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffc223be60 R13: 00007f047c634474 R14: 00000000000facae R15: 00007fffc223bea0 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5358: #0: ffff888035c270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:12/7072: #0: ffff88801e705940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801e705940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9001dd47c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9001dd47c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 2 locks held by syz-executor/17242: #0: ffff888025c4e0d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888025c4e0d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888025c4e0d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509 #1: ffffffff8effea80 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xad/0x530 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/19192: #0: ffff8880889fa0d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880889fa0d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880889fa0d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509 #1: ffffffff8effea80 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xad/0x530 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/20128: #0: ffff88804e8460d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88804e8460d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88804e8460d8 (&type->s_umount_key#76){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509 #1: ffffffff8effea80 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xad/0x530 fs/jfs/jfs_logmgr.c:1441 1 lock held by syz-executor/20182: #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 4 locks held by kworker/u8:14/22392: #0: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675 #1: ffff8880b8624440 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933 #2: ffff8880b8626058 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b8626058 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1a9/0xed0 kernel/time/timer.c:1085 #3: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675 1 lock held by dhcpcd/22493: #0: ffff88807b970260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88807b970260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe90 net/packet/af_packet.c:3226 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 4954 Comm: syslogd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:300 [inline] RIP: 0010:rcu_read_lock include/linux/rcupdate.h:840 [inline] RIP: 0010:is_bpf_text_address+0x41/0x2b0 kernel/bpf/core.c:748 Code: ad ef ff e8 c1 41 d5 ff 48 8d 05 00 00 00 00 48 c7 c7 60 9c b5 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 48 89 44 24 08 <50> e8 59 62 cb ff 48 83 c4 08 e8 10 67 f9 09 89 c5 31 ff 89 c6 e8 RSP: 0018:ffffc9000350f470 EFLAGS: 00000246 RAX: ffffffff81d753b6 RBX: 00007f38cdb73407 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8eb59c60 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffff8880367b0000 R13: 0000000000000000 R14: 00007f38cdb73407 R15: 1ffff920006a1eaa FS: 00007f38cda23c80(0000) GS:ffff888125055000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f81853f14b8 CR3: 0000000021bec000 CR4: 0000000000350ef0 Call Trace: kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x1c5/0x640 mm/slub.c:6692 skb_kfree_head net/core/skbuff.c:1083 [inline] skb_free_head net/core/skbuff.c:1095 [inline] skb_release_data+0x85e/0xab0 net/core/skbuff.c:1122 skb_release_all net/core/skbuff.c:1197 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1211 __unix_dgram_recvmsg+0x9e1/0xd70 net/unix/af_unix.c:2665 sock_recvmsg_nosec net/socket.c:1126 [inline] sock_recvmsg+0x196/0x1e0 net/socket.c:1148 sock_read_iter+0x22a/0x2f0 net/socket.c:1217 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x595/0xa80 fs/read_write.c:574 ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f38cdb73407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fffb9627210 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f38cda23c80 RCX: 00007f38cdb73407 RDX: 00000000000000ff RSI: 000055623c87e950 RDI: 0000000000000000 RBP: 000055623c87e910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055623c87e99d R13: 0000000000000000 R14: 000055623c87e950 R15: 0000556230f47d98