loop6: p1 p3 < > p4 loop6: p4 size 1747 extends beyond EOD, truncated INFO: task syz-executor7:18394 blocked for more than 140 seconds. Not tainted 4.19.0-rc2+ #228 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D10936 18394 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 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+0xa5/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:738 [inline] vfs_unlink+0xd1/0x510 fs/namei.c:3991 do_unlinkat+0x6cc/0xa30 fs/namei.c:4063 __do_sys_unlink fs/namei.c:4110 [inline] __se_sys_unlink fs/namei.c:4108 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4108 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456de7 Code: Bad RIP value. RSP: 002b:00007ffd33a99d58 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456de7 RDX: 00007ffd33a99d70 RSI: 00007ffd33a99e00 RDI: 00007ffd33a99e00 RBP: 0000000000000719 R08: 0000000000000000 R09: 0000000000000013 R10: 0000000000000005 R11: 0000000000000202 R12: 00007ffd33a9aef0 R13: 000000000284b980 R14: 0000000000000000 R15: badc0ffeebadface Showing all locks held in the system: 1 lock held by khungtaskd/985: #0: 000000009e3d6af3 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/5217: #0: 000000003e5ddbd2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5307: #0: 000000000091cbc3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e9ed4c7d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5308: #0: 000000005a10edb3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002a76de34 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5309: #0: 000000008d4af2bf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009dd25f7a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5310: #0: 00000000ba95b9f5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c1af2401 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5311: #0: 0000000037d09ecf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a4f91679 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5312: #0: 00000000560200bf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006dc99d43 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5313: #0: 000000006edb4086 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a51f15ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by syz-executor7/18394: #0: 00000000a4961d69 (sb_writers#5){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 00000000a4961d69 (sb_writers#5){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000673d428b (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:773 [inline] #1: 00000000673d428b (&type->i_mutex_dir_key/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 #2: 00000000d3da2ed0 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:738 [inline] #2: 00000000d3da2ed0 (&sb->s_type->i_mutex_key#13){+.+.}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3991 1 lock held by syz-executor3/684: #0: 0000000014baca14 (&rp->fetch_lock){+.+.}, at: mon_bin_fetch+0x37/0x340 drivers/usb/mon/mon_bin.c:909 3 locks held by syz-executor7/2302: #0: 00000000aabf8156 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000a4961d69 (sb_writers#5){.+.+}, at: file_start_write include/linux/fs.h:2758 [inline] #1: 00000000a4961d69 (sb_writers#5){.+.+}, at: vfs_write+0x42a/0x560 fs/read_write.c:548 #2: 00000000d3da2ed0 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_trylock include/linux/fs.h:758 [inline] #2: 00000000d3da2ed0 (&sb->s_type->i_mutex_key#13){+.+.}, at: ext4_file_write_iter+0x2a1/0x1420 fs/ext4/file.c:232 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 985 Comm: khungtaskd Not tainted 4.19.0-rc2+ #228 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57