INFO: task syz-executor:17473 blocked for more than 143 seconds. Tainted: G W 6.1.122-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20304 pid:17473 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 __writeback_inodes_sb_nr+0x2ce/0x370 fs/fs-writeback.c:2653 sync_filesystem+0xa0/0x220 fs/sync.c:54 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: 0033:0x7f6061587057 RSP: 002b:00007ffc1e281098 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f60616018f4 RCX: 00007f6061587057 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc1e281150 RBP: 00007ffc1e281150 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc1e2821d0 R13: 00007f60616018f4 R14: 00007ffc1e282210 R15: 00000000000000e2 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+0x34/0xde0 kernel/rcu/tasks.h:543 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32bab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x34/0xde0 kernel/rcu/tasks.h:543 1 lock held by khungtaskd/27: #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 2 locks held by getty/4005: #0: ffff888031222098 (&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 2 locks held by kworker/u4:29/13240: 1 lock held by syz-executor/17473: #0: ffff88807cb140e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Tainted: G W 6.1.122-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: 3604 Comm: syslogd Tainted: G W 6.1.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:215 Code: 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 78 6c 10 0d 48 89 de 5b e9 67 bc 56 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0d c4 d2 77 7e 65 8b 15 c5 d2 77 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc90003207928 EFLAGS: 00000283 RAX: ffffffff81e24942 RBX: 00000000000000a8 RCX: ffff88807d8bd940 RDX: ffff88807d8bd940 RSI: 00000000000000a8 RDI: 00000000000000a8 RBP: dffffc0000000000 R08: ffffffff81e24913 R09: fffffbfff2e83589 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88823bcc4000 R13: 1ffffffff2e7afee R14: ffff88823bcc4183 R15: ffffffff973d7f70 FS: 00007fd907297380(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557f2ef6a600 CR3: 0000000031b99000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: for_each_canary mm/kfence/core.c:343 [inline] kfence_guarded_free+0x312/0x7f0 mm/kfence/core.c:499 __unix_dgram_recvmsg+0xcb3/0x1260 net/unix/af_unix.c:2507 sock_recvmsg_nosec net/socket.c:1022 [inline] sock_recvmsg net/socket.c:1040 [inline] sock_read_iter+0x3b2/0x4b0 net/socket.c:1121 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x88d/0xbf0 fs/read_write.c:470 ksys_read+0x19c/0x2c0 fs/read_write.c:613 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: 0033:0x7fd9073ebb6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffc5c681b58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd9073ebb6a RDX: 00000000000000ff RSI: 0000559bd2a72950 RDI: 0000000000000000 RBP: 0000559bd2a72910 R08: 0000000000000001 R09: 0000000000000000 R10: 00007fd90758a3a3 R11: 0000000000000246 R12: 0000559bd2a72999 R13: 0000559bd2a72950 R14: 0000000000000000 R15: 00007fd9075c8a80