INFO: task syz-executor.4:15170 blocked for more than 143 seconds. Not tainted 5.4.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25336 15170 20505 0x00004004 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x7b7/0xc30 kernel/sched/core.c:4078 schedule+0x131/0x1e0 kernel/sched/core.c:4145 io_schedule+0x8b/0x100 kernel/sched/core.c:5789 wait_on_page_bit_common+0x918/0xc90 mm/filemap.c:1175 wait_on_page_bit+0x46/0x50 mm/filemap.c:1224 wait_on_page_writeback+0x13e/0x180 mm/page-writeback.c:2822 __filemap_fdatawait_range+0x1b5/0x3b0 mm/filemap.c:526 file_write_and_wait_range+0x141/0x1a0 mm/filemap.c:786 __generic_file_fsync+0x76/0x1a0 fs/libfs.c:1000 fat_file_fsync+0x7c/0x190 fs/fat/file.c:199 vfs_fsync_range+0xfd/0x1a0 fs/sync.c:197 generic_write_sync include/linux/fs.h:2853 [inline] generic_file_write_iter+0x575/0x630 mm/filemap.c:3470 do_iter_readv_writev+0x651/0x8e0 include/linux/fs.h:1889 do_iter_write+0x180/0x590 fs/read_write.c:970 vfs_iter_write+0x7c/0xa0 fs/read_write.c:983 iter_file_splice_write+0x6d8/0xe20 fs/splice.c:746 do_splice_from fs/splice.c:848 [inline] direct_splice_actor+0xf7/0x130 fs/splice.c:1020 splice_direct_to_actor+0x463/0xac0 fs/splice.c:975 do_splice_direct+0x200/0x330 fs/splice.c:1063 do_sendfile+0x7e4/0xfd0 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1519 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0xfc/0x1b0 fs/read_write.c:1511 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: 03 00 00 48 29 f0 48 3d f8 12 00 00 76 7d 48 81 ec 08 10 00 00 48 89 ac 24 00 10 00 00 48 8d ac 24 00 10 00 00 48 8b 59 20 48 <85> db 75 67 48 8b b4 24 20 10 00 00 8b 8c 24 28 10 00 00 48 89 e7 RSP: 002b:00007efc88da9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a639 RDX: 0000000020000000 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00007efc88daa6d4 R13: 00000000004c83bf R14: 00000000004de7f0 R15: 00000000ffffffff Showing all locks held in the system: 2 locks held by kworker/u4:0/7: #0: ffff8880aeb34998 (&rq->lock){-.-.}, at: newidle_balance+0x629/0xb60 kernel/sched/fair.c:9845 #1: ffffffff888d3e40 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by khungtaskd/1072: #0: ffffffff888d3e40 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by rsyslogd/7736: 2 locks held by getty/7826: #0: ffff88809e9ee090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7827: #0: ffff888096981090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7828: #0: ffff88809fdd4090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7829: #0: ffff8880a842a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7830: #0: ffff88809bd26090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7831: #0: ffff88808d907090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7832: #0: ffff88809c75d090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/15170: #0: ffff8880949c4428 (sb_writers#13){.+.+}, at: file_start_write include/linux/fs.h:2882 [inline] #0: ffff8880949c4428 (sb_writers#13){.+.+}, at: do_sendfile+0x7c2/0xfd0 fs/read_write.c:1463 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1072 Comm: khungtaskd Not tainted 5.4.0-rc8-syzkaller #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+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 kernel/hung_task.c:289 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60