device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 INFO: task syz-executor0:25251 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.20.0-rc6+ #153 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 syz-executor0 D17728 25251 22421 0x00000004 __find_get_block_slow() failed. block=1, b_blocknr=8 Call Trace: b_state=0x00000029, b_size=512 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 schedule+0xfe/0x460 kernel/sched/core.c:3516 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:280 [inline] rwsem_down_read_failed+0x371/0x710 kernel/locking/rwsem-xadd.c:297 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 device loop0 blocksize: 4096 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x9b/0x120 kernel/locking/rwsem.c:26 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 inode_lock_shared include/linux/fs.h:767 [inline] lookup_slow+0x49/0x80 fs/namei.c:1687 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 walk_component+0x92b/0x2590 fs/namei.c:1810 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 filename_lookup+0x26a/0x520 fs/namei.c:2348 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 user_path_at_empty+0x40/0x50 fs/namei.c:2608 __find_get_block_slow() failed. block=1, b_blocknr=8 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x129/0x210 fs/stat.c:185 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 vfs_lstat include/linux/fs.h:3170 [inline] __do_sys_newlstat+0x8f/0x110 fs/stat.c:352 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 __se_sys_newlstat fs/stat.c:346 [inline] __x64_sys_newlstat+0x54/0x80 fs/stat.c:346 b_state=0x00000029, b_size=512 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 entry_SYSCALL_64_after_hwframe+0x49/0xbe device loop0 blocksize: 4096 RIP: 0033:0x457669 __find_get_block_slow() failed. block=1, b_blocknr=8 Code: Bad RIP value. b_state=0x00000029, b_size=512 RSP: 002b:00007f659880fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457669 b_state=0x00000029, b_size=512 RDX: 0000000000000000 RSI: 0000000020000a40 RDI: 0000000020000880 device loop0 blocksize: 4096 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 __find_get_block_slow() failed. block=1, b_blocknr=8 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f65988106d4 b_state=0x00000029, b_size=512 R13: 00000000004c2ca2 R14: 00000000004d4ee0 R15: 00000000ffffffff device loop0 blocksize: 4096 INFO: task syz-executor0:25278 blocked for more than 140 seconds. __find_get_block_slow() failed. block=1, b_blocknr=8 Not tainted 4.20.0-rc6+ #153 b_state=0x00000029, b_size=512 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. device loop0 blocksize: 4096 syz-executor0 D24648 25278 22421 0x00000004 __find_get_block_slow() failed. block=1, b_blocknr=8 Call Trace: b_state=0x00000029, b_size=512 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 schedule+0xfe/0x460 kernel/sched/core.c:3516 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 inode_lock include/linux/fs.h:757 [inline] do_last fs/namei.c:3321 [inline] path_openat+0x15c4/0x5150 fs/namei.c:3534 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 do_filp_open+0x255/0x380 fs/namei.c:3564 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 do_sys_open+0x568/0x700 fs/open.c:1063 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 device loop0 blocksize: 4096 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 entry_SYSCALL_64_after_hwframe+0x49/0xbe __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RIP: 0033:0x457669 b_state=0x00000029, b_size=512 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 device loop0 blocksize: 4096 RSP: 002b:00007f65987acc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 0000000000141042 RDI: 00000000200001c0 __find_get_block_slow() failed. block=1, b_blocknr=8 RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000 b_state=0x00000029, b_size=512 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f65987ad6d4 device loop0 blocksize: 4096 R13: 00000000004f173f R14: 00000000004d5498 R15: 00000000ffffffff Showing all locks held in the system: __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by khungtaskd/1019: b_state=0x00000029, b_size=512 #0: 000000009eb5025d (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 device loop0 blocksize: 4096 1 lock held by rsyslogd/5876: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000d19cacce (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 b_state=0x00000029, b_size=512 2 locks held by getty/5967: #0: 00000000bf6ab615 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 device loop0 blocksize: 4096 #1: 000000005fa540a7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/5968: b_state=0x00000029, b_size=512 #0: 00000000d2e7202a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009662a613 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop0 blocksize: 4096 2 locks held by getty/5969: #0: 0000000033058a1b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000ab197cf3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/5970: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000f7cd293c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000720ee469 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/5971: b_state=0x00000029, b_size=512 #0: 00000000975f55d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 device loop0 blocksize: 4096 #1: 00000000a7ae2907 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/5972: #0: 000000007d9c7dac (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 000000001bee906f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop0 blocksize: 4096 2 locks held by getty/5973: #0: 00000000632698bb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 000000009fcd6b2f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 3 locks held by kworker/u4:7/8119: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000088e6469 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 b_state=0x00000029, b_size=512 #1: 00000000866acdf6 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 device loop0 blocksize: 4096 #2: 000000002ca0a7b8 (&type->s_umount_key#61){++++}, at: trylock_super+0x22/0x110 fs/super.c:412 __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by syz-executor0/25251: b_state=0x00000029, b_size=512 #0: 00000000c0501b54 (&sb->s_type->i_mutex_key#19){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] #0: 00000000c0501b54 (&sb->s_type->i_mutex_key#19){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 device loop0 blocksize: 4096 4 locks held by syz-executor0/25265: 3 locks held by syz-executor0/25275: 2 locks held by syz-executor0/25278: #0: 000000001d27bd34 (sb_writers#12){.+.+}, at: sb_start_write include/linux/fs.h:1597 [inline] #0: 000000001d27bd34 (sb_writers#12){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000c0501b54 (&sb->s_type->i_mutex_key#19){++++}, at: inode_lock include/linux/fs.h:757 [inline] #1: 00000000c0501b54 (&sb->s_type->i_mutex_key#19){++++}, at: do_last fs/namei.c:3321 [inline] #1: 00000000c0501b54 (&sb->s_type->i_mutex_key#19){++++}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 ============================================= NMI backtrace for cpu 1 b_state=0x00000029, b_size=512 CPU: 1 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc6+ #153 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 device loop0 blocksize: 4096 Call Trace: __find_get_block_slow() failed. block=1, b_blocknr=8 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 b_state=0x00000029, b_size=512 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62 device loop0 blocksize: 4096 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 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: __find_get_block_slow() failed. block=1, b_blocknr=8 NMI backtrace for cpu 0 CPU: 0 PID: 25265 Comm: syz-executor0 Not tainted 4.20.0-rc6+ #153 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:200 [inline] RIP: 0010:atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:73 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:87 [inline] RIP: 0010:do_raw_spin_lock+0x17d/0x350 kernel/locking/spinlock_debug.c:113 Code: b8 00 00 00 00 00 fc ff df 48 c1 e9 03 0f b6 04 01 84 c0 74 08 3c 03 0f 8e 61 01 00 00 41 8b 47 c0 b9 01 00 00 00 f0 0f b1 0b <0f> 85 ec 00 00 00 48 b8 00 00 00 00 00 fc ff df 49 c1 ec 03 41 c6 RSP: 0018:ffff88817bbf67b8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff895918a0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88817bbf67e8 RBP: ffff88817bbf6850 R08: ffffed102f77ecfe R09: ffffed102f77ecfd R10: ffffed102f77ecfd R11: 0000000000000003 R12: ffff88817bbf67e8 R13: 1ffff1102f77ecf9 R14: ffffffff895918a8 R15: ffff88817bbf6828 FS: 00007f65987ef700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7b9a9f0000 CR3: 000000017dbd5000 CR4: 00000000001406f0 DR0: 000000000000b8c4 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_lock+0x35/0x40 kernel/locking/spinlock.c:144 console_unlock+0x2ea/0x1190 kernel/printk/printk.c:2354 vprintk_emit+0x391/0x990 kernel/printk/printk.c:1922 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 __find_get_block_slow fs/buffer.c:231 [inline] __find_get_block.cold.57+0x3a/0xff fs/buffer.c:1294 __getblk_slow fs/buffer.c:1039 [inline] __getblk_gfp+0x2b3/0xd50 fs/buffer.c:1320 __bread_gfp+0x2d/0x310 fs/buffer.c:1354 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_open+0x72e/0x1b90 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x2464/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 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:00007f65987eec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f65987ef6d4 R13: 00000000004f173f R14: 00000000004d5498 R15: 00000000ffffffff INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.319 msecs b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8