INFO: task syz-executor:4265 blocked for more than 145 seconds. Not tainted 6.1.128-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21056 pid:4265 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 rwsem_down_write_slowpath+0xea1/0x14b0 kernel/locking/rwsem.c:1189 deactivate_super+0xa9/0xe0 fs/super.c:362 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f10d638e117 RSP: 002b:00007ffedeb3ed88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f10d640e08c RCX: 00007f10d638e117 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffedeb3ee40 RBP: 00007ffedeb3ee40 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffedeb3fed0 R13: 00007f10d640e08c R14: 0000000000034108 R15: 00007ffedeb3ff10 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b290 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32ba90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 3 locks held by kworker/u4:2/33: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90000aa7d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 2 locks held by getty/4009: #0: ffff88814d147098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/4265: #0: ffff888079abe0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 5 locks held by kworker/u4:18/4953: #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90004527d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4ffad0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594 #3: ffffffff8e50bfa8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0xc0/0x460 net/ipv6/ip6_gre.c:1666 #4: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #4: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 3 locks held by ext4lazyinit/6002: 2 locks held by kworker/0:9/6235: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90003cc7d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 2 locks held by kworker/u4:21/6441: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90005547d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 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+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 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: 6002 Comm: ext4lazyinit Not tainted 6.1.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data kernel/kcov.c:244 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x80 kernel/kcov.c:320 Code: 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 c3 0f 1f 00 4c 8b 04 24 <65> 48 8b 0d b4 ce 77 7e 65 8b 05 b5 ce 77 7e 25 00 01 ff 00 74 10 RSP: 0018:ffffc9000d74fa38 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000109 RCX: ffff888053cc9dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000d74fb78 R08: ffffffff82015e2a R09: fffff9400039247f R10: 0000000000000000 R11: dffffc0000000001 R12: fffffffffffffff6 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000036948 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f573a979178 CR3: 0000000026d02000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lookup_bh_lru fs/buffer.c:1276 [inline] __find_get_block+0x1ba/0x1120 fs/buffer.c:1303 __getblk_slow fs/buffer.c:1034 [inline] __getblk_gfp+0x146/0xa20 fs/buffer.c:1333 sb_getblk include/linux/buffer_head.h:356 [inline] ext4_read_block_bitmap_nowait+0x1ff/0x980 fs/ext4/balloc.c:482 ext4_mb_prefetch+0x46d/0x640 fs/ext4/mballoc.c:2587 ext4_run_li_request fs/ext4/super.c:3644 [inline] ext4_lazyinit_thread+0x54d/0x1ad0 fs/ext4/super.c:3770 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295