device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 INFO: task syz-executor4:6119 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.20.0-rc6+ #374 device loop4 blocksize: 4096 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. __find_get_block_slow() failed. block=1, b_blocknr=8 syz-executor4 D18616 6119 1 0x00000004 b_state=0x00000029, b_size=512 Call Trace: device loop4 blocksize: 4096 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 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 loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:280 [inline] rwsem_down_read_failed+0x371/0x710 kernel/locking/rwsem-xadd.c:297 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 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 loop4 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 loop4 blocksize: 4096 walk_component+0x92b/0x2590 fs/namei.c:1810 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 link_path_walk fs/namei.c:2072 [inline] path_openat+0x270/0x5150 fs/namei.c:3533 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 do_filp_open+0x255/0x380 fs/namei.c:3564 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 do_sys_open+0x568/0x700 fs/open.c:1063 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 __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 b_state=0x00000029, b_size=512 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 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 loop4 blocksize: 4096 RIP: 0033:0x455670 __find_get_block_slow() failed. block=1, b_blocknr=8 Code: Bad RIP value. b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 RSP: 002b:00007ffedd015e20 EFLAGS: 00000202 ORIG_RAX: 0000000000000002 __find_get_block_slow() failed. block=1, b_blocknr=8 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455670 b_state=0x00000029, b_size=512 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004bc3ae device loop4 blocksize: 4096 RBP: 00000000000003e6 R08: 0000000000000001 R09: 0000000000ecc940 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000006 R13: 00000000000549a8 R14: 00000000000000db R15: 0000000000000004 INFO: task syz-executor4:13701 blocked for more than 140 seconds. __find_get_block_slow() failed. block=1, b_blocknr=8 Not tainted 4.20.0-rc6+ #374 b_state=0x00000029, b_size=512 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24632 13701 6119 0x00000004 device loop4 blocksize: 4096 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 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 loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 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 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 inode_lock include/linux/fs.h:757 [inline] do_last fs/namei.c:3321 [inline] path_openat+0x15c4/0x5150 fs/namei.c:3534 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 do_filp_open+0x255/0x380 fs/namei.c:3564 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 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 loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 __find_get_block_slow() failed. block=1, b_blocknr=8 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 entry_SYSCALL_64_after_hwframe+0x49/0xbe 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:00007f26a3546c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457669 RDX: 0000000000002761 RSI: 0000000020000200 RDI: ffffffffffffffff device loop4 blocksize: 4096 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f26a35476d4 __find_get_block_slow() failed. block=1, b_blocknr=8 R13: 00000000004c3024 R14: 00000000004d5600 R15: 00000000ffffffff Showing all locks held in the system: b_state=0x00000029, b_size=512 1 lock held by khungtaskd/1019: device loop4 blocksize: 4096 #0: 0000000071e669cb (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by rsyslogd/5883: b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000538a5599 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 b_state=0x00000029, b_size=512 2 locks held by getty/5973: device loop4 blocksize: 4096 #0: 00000000f4944a2f (&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: 000000001180969c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 2 locks held by getty/5974: #0: 000000000a4bbe2d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 device loop4 blocksize: 4096 #1: 00000000c4a31c45 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5975: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000008b232dbe (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 00000000a1020111 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5976: #0: 00000000da739cbb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 device loop4 blocksize: 4096 #1: 00000000b98390c1 (&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/5977: #0: 000000004d3c64b9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 #1: 00000000cc4b9469 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop4 blocksize: 4096 2 locks held by getty/5978: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000e2523af9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 00000000592544d8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop4 blocksize: 4096 2 locks held by getty/5979: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 0000000098054a64 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 000000003c3c9c9e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop4 blocksize: 4096 1 lock held by syz-executor4/6119: #0: 00000000fc6c7180 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] #0: 00000000fc6c7180 (&sb->s_type->i_mutex_key#20){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 __find_get_block_slow() failed. block=1, b_blocknr=8 7 locks held by syz-executor4/13682: b_state=0x00000029, b_size=512 2 locks held by syz-executor4/13701: #0: 000000003e108404 (sb_writers#12){.+.+}, at: sb_start_write include/linux/fs.h:1597 [inline] #0: 000000003e108404 (sb_writers#12){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000fc6c7180 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock include/linux/fs.h:757 [inline] #1: 00000000fc6c7180 (&sb->s_type->i_mutex_key#20){++++}, at: do_last fs/namei.c:3321 [inline] #1: 00000000fc6c7180 (&sb->s_type->i_mutex_key#20){++++}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534 device loop4 blocksize: 4096 ============================================= __find_get_block_slow() failed. block=1, b_blocknr=8 NMI backtrace for cpu 0 b_state=0x00000029, b_size=512 CPU: 0 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc6+ #374 device loop4 blocksize: 4096 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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 device loop4 blocksize: 4096 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 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 kthread+0x35a/0x440 kernel/kthread.c:246 device loop4 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 b_state=0x00000029, b_size=512 Sending NMI from CPU 0 to CPUs 1: device loop4 blocksize: 4096 NMI backtrace for cpu 1 CPU: 1 PID: 13682 Comm: syz-executor4 Not tainted 4.20.0-rc6+ #374 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data+0x0/0x70 kernel/kcov.c:116 Code: e8 c5 66 43 00 e9 a6 fc ff ff 4c 89 f7 e8 18 66 43 00 e9 6f fc ff ff e8 ae 64 c9 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 65 4c 8b 04 25 40 ee 01 00 65 8b 05 bc 69 82 7e a9 00 RSP: 0018:ffff88817d7765f8 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000007 RCX: ffffffff87d70900 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000001 RBP: ffff88817d776628 R08: ffff88817ca463c0 R09: ffffed102faeecfb R10: ffffed102faeecfb R11: 0000000000000003 R12: ffffffff88d7f860 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000008 FS: 00007f26a3568700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b60ac000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x1c0/0x1b60 lib/vsprintf.c:2252 sprintf+0xb0/0xe0 lib/vsprintf.c:2498 print_time kernel/printk/printk.c:1228 [inline] print_prefix+0x26a/0x3f0 kernel/printk/printk.c:1251 msg_print_text+0xcc/0x1d0 kernel/printk/printk.c:1278 console_unlock+0x4e6/0x1190 kernel/printk/printk.c:2388 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:237 [inline] __find_get_block.cold.57+0xd8/0xff 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+0x15e4/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 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:00007f26a3567c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457669 RDX: 0000000000002761 RSI: 0000000020000200 RDI: ffffffffffffffff RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f26a35686d4 R13: 00000000004c3024 R14: 00000000004d5600 R15: 00000000ffffffff