INFO: task syz-executor:4403 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22048 pid:4403 ppid:1 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 jfs_umount+0x28f/0x360 fs/jfs/jfs_umount.c:116 jfs_put_super+0x88/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f31347901f7 RSP: 002b:00007ffd9f7d1c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f3134811d7d RCX: 00007f31347901f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd9f7d1d20 RBP: 00007ffd9f7d1d20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd9f7d2db0 R13: 00007f3134811d7d R14: 000000000003560f R15: 00007ffd9f7d2df0 INFO: task syz-executor:4412 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22240 pid:4412 ppid:1 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 jfs_umount+0x28f/0x360 fs/jfs/jfs_umount.c:116 jfs_put_super+0x88/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc588d901f7 RSP: 002b:00007ffc39fa4d28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fc588e11d7d RCX: 00007fc588d901f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc39fa4de0 RBP: 00007ffc39fa4de0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc39fa5e70 R13: 00007fc588e11d7d R14: 000000000003522e R15: 00007ffc39fa5eb0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b570 (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: ffffffff8cb2bd90 (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: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4026: #0: ffff88814d5c1098 (&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 2 locks held by syz-executor/4396: #0: ffff88807724c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4403: #0: ffff8880772920e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4412: #0: ffff88807b5460e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 3 locks held by kworker/u4:8/4482: 2 locks held by syz-executor/4541: #0: ffff8880595460e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4568: #0: ffff888026a1c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4570: #0: ffff8880759340e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4572: #0: ffff88807d7860e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4589: #0: ffff888075cee0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/4678: #0: ffff8880699f40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cf27c68 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1444 1 lock held by syz-executor/4723: #0: ffff88807fe6e0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 1 lock held by udevd/4764: 2 locks held by syz.2.503/5302: 2 locks held by syz.3.504/5303: 2 locks held by syz.7.505/5304: ============================================= 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 08/18/2025 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: 4818 Comm: udevd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:169 [inline] RIP: 0010:unwind_next_frame+0x1d3/0x20b0 arch/x86/kernel/unwind_orc.c:448 Code: f4 17 00 00 44 89 f0 4c 8d 24 85 40 fe 3d 8f 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 4d 89 ef 0f 85 57 19 00 00 45 8b 24 24 <44> 89 f0 ff c0 4c 8d 2c 85 40 fe 3d 8f 4c 89 e8 48 c1 e8 03 42 0f RSP: 0018:ffffc900047d7730 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc900047d7808 RCX: ffffffff96be9100 RDX: dffffc0000000000 RSI: 0000000000096078 RDI: ffffffff8138651f RBP: ffffffff81deb532 R08: ffffc900047d78d0 R09: 0000000000000006 R10: fffff520008faf0d R11: 1ffff920008faf0b R12: 000000000002e979 R13: dffffc0000000000 R14: 000000000000deb5 R15: dffffc0000000000 FS: 00007f6c8b36b880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb7afbfe000 CR3: 000000007c653000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node+0xb0/0x240 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x6c/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:716 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x1f6/0xd50 fs/seq_file.c:210 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x434/0x920 fs/read_write.c:470 ksys_read+0x143/0x240 fs/read_write.c:613 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: 0033:0x7f6c8aca7407 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:00007ffcff078db0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f6c8b36b880 RCX: 00007f6c8aca7407 RDX: 0000000000001000 RSI: 000055eaacc1fa00 RDI: 0000000000000009 RBP: 00007f6c8adefff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f6c8adefea0 R14: 0000000000000000 R15: 000055eaacc1d7a0