syz-executor0(7767): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(7767): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(7767): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(7767): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(7767): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor0:7801 blocked for more than 140 seconds. Not tainted 4.20.0-rc6-next-20181214+ #171 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D24696 7801 25145 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0xa41/0x21e0 kernel/sched/core.c:3472 schedule+0xef/0x370 kernel/sched/core.c:3516 d_wait_lookup fs/dcache.c:2408 [inline] d_alloc_parallel+0x1478/0x1f40 fs/dcache.c:2490 __lookup_slow+0x1e6/0x540 fs/namei.c:1654 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x2590 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] do_linkat+0x188/0xa90 fs/namei.c:4290 __do_sys_link fs/namei.c:4338 [inline] __se_sys_link fs/namei.c:4336 [inline] __x64_sys_link+0x5e/0x80 fs/namei.c:4336 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457679 Code: Bad RIP value. RSP: 002b:00007fde2ca57c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000056 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457679 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000020000240 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde2ca586d4 R13: 00000000004f6b33 R14: 00000000004d4cf0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1024: #0: 00000000fbe35891 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5913: #0: 00000000f2476a91 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6026: #0: 00000000df4dbc49 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000195f7232 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by getty/6027: #0: 000000004f207eef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f9f0ed2f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by getty/6028: #0: 00000000c2eec2e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003dc31426 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by getty/6029: #0: 0000000029af58ea (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000003154a09 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by getty/6030: #0: 00000000563709d2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002088c296 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by getty/6031: #0: 0000000033db5d4c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009a50dd98 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by getty/6032: #0: 00000000f2182fc6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005d7031c7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ee0 drivers/tty/n_tty.c:2154 2 locks held by syz-executor0/7767: 1 lock held by syz-executor0/7801: #0: 00000000b7db5119 (&sb->s_type->i_mutex_key#27){++++}, at: inode_lock_shared include/linux/fs.h:781 [inline] #0: 00000000b7db5119 (&sb->s_type->i_mutex_key#27){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1024 Comm: khungtaskd Not tainted 4.20.0-rc6-next-20181214+ #171 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.570 msecs NMI backtrace for cpu 1 CPU: 1 PID: 7767 Comm: syz-executor0 Not tainted 4.20.0-rc6-next-20181214+ #171 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:94 Code: 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 55 48 89 e5 <48> 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 98 ea 81 7e 81 e2 RSP: 0018:ffff8881864e63e8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff11030c9cc82 RCX: ffffc90012196000 RDX: 0000000000040000 RSI: ffffffff819e6550 RDI: 0000000000000001 RBP: ffff8881864e63e8 R08: ffff888109d6e140 R09: 0000000000000008 R10: 0000000000000050 R11: ffff888109d6e140 R12: 000000000002db00 R13: ffff8881864e6470 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007fde2ca9a700(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000aeb978 CR3: 00000001836e9000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: debug_smp_processor_id+0x9/0x20 lib/smp_processor_id.c:56 rcu_dynticks_curr_cpu_in_eqs+0x69/0x170 kernel/rcu/tree.c:303 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:932 rcu_read_lock include/linux/rcupdate.h:608 [inline] find_get_entry+0xce5/0x1120 mm/filemap.c:1473 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1579 find_get_page_flags include/linux/pagemap.h:278 [inline] __find_get_block_slow fs/buffer.c:205 [inline] __find_get_block+0x63a/0xf20 fs/buffer.c:1325 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3d3/0x1030 fs/buffer.c:1351 __bread_gfp+0x2d/0x310 fs/buffer.c:1385 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x5a6/0xa40 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x1570 fs/fat/dir.c:479 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x2590 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] do_linkat+0x188/0xa90 fs/namei.c:4290 __do_sys_link fs/namei.c:4338 [inline] __se_sys_link fs/namei.c:4336 [inline] __x64_sys_link+0x5e/0x80 fs/namei.c:4336 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457679 Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fde2ca99c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000056 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457679 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000020000240 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde2ca9a6d4 R13: 00000000004f6b33 R14: 00000000004d4cf0 R15: 00000000ffffffff