Hello, syzbot found the following issue on: HEAD commit: 076d56d74f17 Add linux-next specific files for 20240202 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=173b568fe80000 kernel config: https://syzkaller.appspot.com/x/.config?x=428086ff1c010d9f dashboard link: https://syzkaller.appspot.com/bug?extid=0260338e3eff65854d1f compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=148b3c9fe80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13811004180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/dece45d1a4b5/disk-076d56d7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4921e269b178/vmlinux-076d56d7.xz kernel image: https://storage.googleapis.com/syzbot-assets/2a9156da9091/bzImage-076d56d7.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/9938609b8cc3/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0260338e3eff65854d1f@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor218:5106 blocked for more than 143 seconds. Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor218 state:D stack:18928 pid:5106 tgid:5106 ppid:5102 flags:0x00004002 Call Trace: <TASK> context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17df/0x4a40 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6804 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6819 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617 xfs_inodegc_wait_all fs/xfs/xfs_icache.c:465 [inline] xfs_inodegc_flush+0xe1/0x3e0 fs/xfs/xfs_icache.c:1912 xfs_unmountfs+0x25/0x200 fs/xfs/xfs_mount.c:1064 xfs_fs_put_super+0x65/0x140 fs/xfs/xfs_super.c:1136 generic_shutdown_super+0x136/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1680 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2026 deactivate_locked_super+0xc4/0x130 fs/super.c:477 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:108 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f1a396ed8f7 RSP: 002b:00007ffec055f888 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f1a396ed8f7 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffec055f940 RBP: 00007ffec055f940 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffec05609b0 R13: 000055555739d6c0 R14: 00000000000c93c9 R15: 0000000000000108 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4817: #0: ffff88802a9230a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by syz-executor218/5106: #0: ffff88807f4d40e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807f4d40e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807f4d40e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:509 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfb0/0xff0 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 --- This report is generated by a bot. 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