INFO: task syz-executor:4259 blocked for more than 145 seconds. Not tainted 6.1.114-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20464 pid:4259 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 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 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: 0033:0x7fa6c437fa47 RSP: 002b:00007fff7e0372b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fa6c43f11cc RCX: 00007fa6c437fa47 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff7e037370 RBP: 00007fff7e037370 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff7e0383f0 R13: 00007fa6c43f11cc R14: 000000000002f27c R15: 00007fff7e038430 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b1d0 (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: ffffffff8d32b9d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 3 locks held by kworker/1:1/27: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90000a3fd20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 1 lock held by khungtaskd/28: #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by kworker/u4:2/33: 2 locks held by getty/4011: #0: ffff888031223098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900032462f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 2 locks held by syz-executor/4259: #0: ffff8880299e00e0 (&type->s_umount_key#77){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff8880250507d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8880250507d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 2 locks held by kworker/1:6/4341: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000498fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 4 locks held by kworker/u4:15/4647: 1 lock held by cmp/6621: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.114-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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: 6622 Comm: syz.8.430 Not tainted 6.1.114-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x45/0x60 kernel/kcov.c:222 Code: 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 <8b> 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 c3 0f 1f RSP: 0018:ffffc9001b2a7920 EFLAGS: 00000246 RAX: ffffffff81cdd0a3 RBX: ffff88802599a2e8 RCX: ffff888025999dc0 RDX: ffffc9000c679000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffff888017c6d280 R08: ffffffff81cdd05c R09: ffffc9001b2a79e0 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: dffffc0000000000 R14: 000000000000000e R15: 1ffff11004b3345d FS: 00007fececa1c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9945483318 CR3: 0000000073b5e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __might_fault+0x93/0x110 mm/memory.c:5851 _copy_from_user+0x26/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:161 [inline] copy_msghdr_from_user+0xaa/0x670 net/socket.c:2449 recvmsg_copy_msghdr net/socket.c:2704 [inline] ___sys_recvmsg net/socket.c:2776 [inline] do_recvmmsg+0x408/0xad0 net/socket.c:2874 __sys_recvmmsg net/socket.c:2953 [inline] __do_sys_recvmmsg net/socket.c:2976 [inline] __se_sys_recvmmsg net/socket.c:2969 [inline] __x64_sys_recvmmsg+0x195/0x240 net/socket.c:2969 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fecebb7e719 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fececa1c038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fecebd36058 RCX: 00007fecebb7e719 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fecebbf132e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fecebd36058 R15: 00007ffcf8f6cb68 vkms_vblank_simulate: vblank timer overrun