device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 INFO: task syz-executor0:18952 blocked for more than 120 seconds. b_state=0x00000029, b_size=4096 Not tainted 4.16.0+ #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D device loop0 blocksize: 2048 23408 18952 4518 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 schedule+0xf5/0x430 kernel/sched/core.c:3499 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 __rwsem_down_write_failed_common+0x7c0/0x1540 kernel/locking/rwsem-xadd.c:566 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 b_state=0x00000029, b_size=4096 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+0xa2/0x120 kernel/locking/rwsem.c:72 device loop0 blocksize: 2048 inode_lock include/linux/fs.h:713 [inline] do_last fs/namei.c:3288 [inline] path_openat+0xd4d/0x3530 fs/namei.c:3519 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 do_filp_open+0x25b/0x3b0 fs/namei.c:3554 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 do_sys_open+0x502/0x6d0 fs/open.c:1059 device loop0 blocksize: 2048 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 entry_SYSCALL_64_after_hwframe+0x42/0xb7 __find_get_block_slow() failed. block=1, b_blocknr=0 RIP: 0033:0x455269 RSP: 002b:00007f238ff68c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f238ff696d4 RCX: 0000000000455269 b_state=0x00000029, b_size=4096 RDX: 0000000000000001 RSI: 0000000000000040 RDI: 00000000200000c0 RBP: 000000000072c010 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000415 R14: 00000000006f8298 R15: 0000000000000002 device loop0 blocksize: 2048 Showing all locks held in the system: 2 locks held by khungtaskd/876: __find_get_block_slow() failed. block=1, b_blocknr=0 #0: (rcu_read_lock){....}, at: [<000000005bb25299>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000005bb25299>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 b_state=0x00000029, b_size=4096 #1: (tasklist_lock){.+.+}, at: [<000000006f81baf1>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4441: device loop0 blocksize: 2048 #0: (&tty->ldisc_sem){++++}, at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: __find_get_block_slow() failed. block=1, b_blocknr=0 (&ldata->atomic_read_lock){+.+.}, at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4442: b_state=0x00000029, b_size=4096 #0: (&tty->ldisc_sem){++++}, at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.} device loop0 blocksize: 2048 , at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4443: #0: ( __find_get_block_slow() failed. block=1, b_blocknr=0 &tty->ldisc_sem){++++}, at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: b_state=0x00000029, b_size=4096 (&ldata->atomic_read_lock){+.+.}, at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4444: #0: (&tty->ldisc_sem device loop0 blocksize: 2048 ){++++}, at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4445: #0: __find_get_block_slow() failed. block=1, b_blocknr=0 (&tty->ldisc_sem){++++}, at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: b_state=0x00000029, b_size=4096 (&ldata->atomic_read_lock){+.+.}, at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4446: #0: (&tty->ldisc_sem){++++} device loop0 blocksize: 2048 , at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock __find_get_block_slow() failed. block=1, b_blocknr=0 ){+.+.}, at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4447: #0: b_state=0x00000029, b_size=4096 (&tty->ldisc_sem){++++}, at: [<0000000074c0e66e>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.} device loop0 blocksize: 2048 , at: [<000000008c1cd734>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by syz-executor0/18952: #0: ( __find_get_block_slow() failed. block=1, b_blocknr=0 sb_writers#16){.+.+}, at: [<000000009472eb1c>] sb_start_write include/linux/fs.h:1548 [inline] sb_writers#16){.+.+}, at: [<000000009472eb1c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: b_state=0x00000029, b_size=4096 (&sb->s_type->i_mutex_key#19){++++}, at: [<000000000c72d3c0>] inode_lock include/linux/fs.h:713 [inline] (&sb->s_type->i_mutex_key#19){++++}, at: [<000000000c72d3c0>] do_last fs/namei.c:3288 [inline] (&sb->s_type->i_mutex_key#19){++++}, at: [<000000000c72d3c0>] path_openat+0xd4d/0x3530 fs/namei.c:3519 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 876 Comm: khungtaskd Not tainted 4.16.0+ #10 device loop0 blocksize: 2048 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 __find_get_block_slow() failed. block=1, b_blocknr=0 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 b_state=0x00000029, b_size=4096 nmi_trigger_cpumask_backtrace+0x123/0x180 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 kthread+0x33c/0x400 kernel/kthread.c:238 b_state=0x00000029, b_size=4096 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18900 Comm: syz-executor0 Not tainted 4.16.0+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vsnprintf+0x2a8/0x1900 lib/vsprintf.c:2241 RSP: 0018:ffff88019bec69c0 EFLAGS: 00000046 RAX: 0000000000040000 RBX: ffffffff89db2120 RCX: ffffffff86e20d88 RDX: 0000000000040000 RSI: ffffc90001ee0000 RDI: ffffffff874ad700 RBP: ffff88019bec6a90 R08: 1ffff100337d8cbf R09: 000000000000000c R10: ffff88019bec6b70 R11: 0000000000000000 R12: ffffffff874ad700 R13: ffffffff874ad701 R14: ffff88019bec6a68 R15: 0000000000000000 FS: 00007f238ffab700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002378000 CR3: 00000001c64b6005 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sprintf+0xb8/0xf0 lib/vsprintf.c:2484 print_time kernel/printk/printk.c:1223 [inline] print_prefix+0x335/0x3a0 kernel/printk/printk.c:1246 msg_print_text+0xaf/0x1b0 kernel/printk/printk.c:1273 console_unlock+0x308/0xfb0 kernel/printk/printk.c:2369 vprintk_emit+0x5c3/0xb90 kernel/printk/printk.c:1907 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 __find_get_block_slow fs/buffer.c:236 [inline] __find_get_block+0xcea/0xd90 fs/buffer.c:1310 __getblk_slow fs/buffer.c:1055 [inline] __getblk_gfp+0x26c/0xb80 fs/buffer.c:1336 __bread_gfp+0x2d/0x290 fs/buffer.c:1370 sb_bread include/linux/buffer_head.h:309 [inline] fat__get_entry+0x195/0x910 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_get_short_entry+0x131/0x290 fs/fat/dir.c:876 fat_scan+0xf9/0x330 fs/fat/dir.c:961 msdos_find+0xf9/0x2e0 fs/fat/namei_msdos.c:129 msdos_lookup+0x136/0x2e0 fs/fat/namei_msdos.c:209 lookup_open+0xb1b/0x1970 fs/namei.c:3179 do_last fs/namei.c:3291 [inline] path_openat+0xd76/0x3530 fs/namei.c:3519 do_filp_open+0x25b/0x3b0 fs/namei.c:3554 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x455269 RSP: 002b:00007f238ffaac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f238ffab6d4 RCX: 0000000000455269 RDX: 0000000000000001 RSI: 0000000000000040 RDI: 00000000200000c0 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000415 R14: 00000000006f8298 R15: 0000000000000000 Code: c3 01 0f b6 04 30 38 d0 7f 08 84 c0 0f 85 10 13 00 00 45 0f b6 7d 00 4d 89 ec e9 a5 fe ff ff 48 89 8d 38 ff ff ff e8 b8 57 8f fa <4c> 8b bd 60 ff ff ff 48 8b 8d 38 ff ff ff 4c 39 fb 73 5f e8 a0