INFO: task syz-executor.3:11019 blocked for more than 140 seconds. Not tainted 4.19.82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27800 11019 7593 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:747 [inline] lock_mount+0x8c/0x2e0 fs/namespace.c:2039 do_add_mount+0x27/0x380 fs/namespace.c:2416 do_new_mount fs/namespace.c:2483 [inline] do_mount+0x160a/0x2bc0 fs/namespace.c:2799 ksys_mount+0xdb/0x150 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3026 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: Bad RIP value. RSP: 002b:00007f111aeb0c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a219 RDX: 0000000020000300 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075bfc8 R08: 00000000200005c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f111aeb16d4 R13: 00000000004c6d0d R14: 00000000004dc520 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1038: #0: 000000000bc5a889 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7420: 2 locks held by getty/7543: #0: 00000000d286e890 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000852b7f53 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7544: #0: 00000000b9ccd470 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000036a8e1b7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7545: #0: 000000002984cdda (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000006e0dac37 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7546: #0: 000000001885dd63 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000000114de27 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7547: #0: 00000000721e7e82 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000cce1d413 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7548: #0: 000000005058436d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000008fa7ff59 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7549: #0: 0000000099a861fa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000000431b4c8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.3/10574: #0: 0000000071871c81 (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1578 [inline] #0: 0000000071871c81 (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000006d2b7c19 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:782 [inline] #1: 000000006d2b7c19 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3635 1 lock held by syz-executor.3/11019: #0: 000000006d2b7c19 (&sb->s_type->i_mutex_key#21){++++}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000006d2b7c19 (&sb->s_type->i_mutex_key#21){++++}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2039 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1038 Comm: khungtaskd Not tainted 4.19.82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60