INFO: task syz-executor.4:17859 blocked for more than 143 seconds. Not tainted 5.4.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25328 17859 8847 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 io_schedule+0x1c/0x70 kernel/sched/core.c:5799 wait_on_page_bit_common mm/filemap.c:1175 [inline] wait_on_page_bit+0x27c/0xa60 mm/filemap.c:1224 wait_on_page_writeback+0x1b2/0x4f0 mm/page-writeback.c:2822 __filemap_fdatawait_range+0x145/0x340 mm/filemap.c:526 file_write_and_wait_range+0x1ac/0x210 mm/filemap.c:786 __generic_file_fsync+0x79/0x200 fs/libfs.c:1000 fat_file_fsync+0x78/0x210 fs/fat/file.c:199 vfs_fsync_range+0x141/0x230 fs/sync.c:197 generic_write_sync include/linux/fs.h:2849 [inline] generic_file_write_iter+0x4ea/0x690 mm/filemap.c:3470 call_write_iter include/linux/fs.h:1895 [inline] do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x184/0x610 fs/read_write.c:951 vfs_iter_write+0x77/0xb0 fs/read_write.c:983 iter_file_splice_write+0x66d/0xbe0 fs/splice.c:746 do_splice_from fs/splice.c:848 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1020 splice_direct_to_actor+0x366/0x970 fs/splice.c:975 do_splice_direct+0x1da/0x2a0 fs/splice.c:1063 do_sendfile+0x597/0xd00 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+0x15a/0x220 fs/read_write.c:1511 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: f3 a4 48 8b 94 24 18 10 00 00 ff 12 48 8b 94 24 10 10 00 00 48 8b bc 24 20 10 00 00 8b 8c 24 28 10 00 00 8b 9c 24 2c 10 00 00 <48> 89 e6 48 01 df 48 01 de 48 29 d9 e8 c6 fa ff ff 48 8b ac 24 00 RSP: 002b:00007fa70e038c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a679 RDX: 0000000020000000 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00007fa70e0396d4 R13: 00000000004c863e R14: 00000000004df330 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1090: #0: ffffffff891a4080 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 1 lock held by rsyslogd/8705: 2 locks held by getty/8795: #0: ffff88808b992090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f552e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8796: #0: ffff8880a1381090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f512e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8797: #0: ffff8880942c0090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f592e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8798: #0: ffff888099827090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f5d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8799: #0: ffff88809730d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8800: #0: ffff888094d7d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8801: #0: ffff8880a59ab090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/17859: #0: ffff8880913d2428 (sb_writers#15){.+.+}, at: file_start_write include/linux/fs.h:2878 [inline] #0: ffff8880913d2428 (sb_writers#15){.+.+}, at: do_sendfile+0x9b9/0xd00 fs/read_write.c:1463 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1090 Comm: khungtaskd Not tainted 5.4.0-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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 kthread+0x361/0x430 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 CPU: 1 PID: 29163 Comm: kworker/u4:5 Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:95 Code: 89 25 a4 27 5e 09 41 bc f4 ff ff ff e8 9d 52 e9 ff 48 c7 05 8e 27 5e 09 00 00 00 00 e9 f2 e5 ff ff cc cc cc cc cc cc cc cc cc <55> 48 89 e5 65 48 8b 04 25 c0 1e 02 00 65 8b 15 54 40 8d 7e 81 e2 RSP: 0018:ffff888067adfc80 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff83531e0a RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff888067adfc98 R08: ffff8880538e6040 R09: ffffed1015d27045 R10: ffffed1015d27044 R11: ffff8880ae938223 R12: 0000000000000001 R13: 00000000000000c4 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42a4e7000 CR3: 0000000096129000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs+0x17/0xb0 kernel/rcu/tree.c:299 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:922 rcu_read_unlock include/linux/rcupdate.h:667 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x480/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352