INFO: task syz-executor.0:21352 can't die for more than 143 seconds. syz-executor.0 R running task 27112 21352 20239 0x00004006 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4069 INFO: task syz-executor.0:21357 can't die for more than 143 seconds. syz-executor.0 R running task 27152 21357 20239 0x00004006 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4069 Showing all locks held in the system: 1 lock held by khungtaskd/1073: #0: ffffffff88fab740 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by rsyslogd/8481: #0: ffff88809409d5e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8570: #0: ffff88809e76b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8571: #0: ffff88808ff5d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8572: #0: ffff88808feca090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f432e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8573: #0: ffff888093752090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8574: #0: ffff88809919e090 (&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+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8575: #0: ffff88809f370090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8576: #0: ffff8880a4722090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/21352: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1073 Comm: khungtaskd Not tainted 5.4.0-rc3-next-20191018 #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+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:269 [inline] watchdog+0xc8f/0x1350 kernel/hung_task.c:353 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: 21357 Comm: syz-executor.0 Not tainted 5.4.0-rc3-next-20191018 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:page_is_mergeable block/bio.c:635 [inline] RIP: 0010:__bio_try_merge_page+0x162/0x3b0 block/bio.c:757 Code: 03 0f b6 0c 11 48 89 fa 83 e2 07 48 c1 f8 06 83 c2 03 48 c1 e0 0c 38 ca 7c 08 84 c9 0f 85 ce 01 00 00 49 8d 7f 08 41 8b 77 0c <48> ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 0c 11 84 RSP: 0018:ffff888058437b70 EFLAGS: 00000246 RAX: 000000000a04b000 RBX: ffff88809a0bfc80 RCX: 0000000000000000 RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff8880191b71b8 RBP: ffff888058437bb0 R08: ffff8880997a22c0 R09: fffff94000050259 R10: fffff94000050258 R11: ffffea00002812c7 R12: 0000000000000000 R13: ffffea00002812c0 R14: ffff888058437be8 R15: ffff8880191b71b0 FS: 00007fc662c51700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42c31b228 CR3: 00000000a94e9000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bio_add_page+0x88/0x220 block/bio.c:812 __blkdev_issue_zero_pages+0x2e3/0x430 block/blk-lib.c:292 blkdev_issue_zeroout+0x434/0x4c0 block/blk-lib.c:378 blkdev_fallocate+0x2fc/0x410 fs/block_dev.c:2089 vfs_fallocate+0x4aa/0xa50 fs/open.c:309 ksys_fallocate+0x58/0xa0 fs/open.c:332 __do_sys_fallocate fs/open.c:340 [inline] __se_sys_fallocate fs/open.c:338 [inline] __x64_sys_fallocate+0x97/0xf0 fs/open.c:338 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459a59 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc662c50c78 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459a59 RDX: 0000000000000000 RSI: 0000000000000011 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000400000000200 R11: 0000000000000246 R12: 00007fc662c516d4 R13: 00000000004c01d8 R14: 00000000004d26f0 R15: 00000000ffffffff