syzbot


INFO: task hung in nmi_cpu_backtrace

Status: auto-closed as invalid on 2019/02/22 13:59
First crash: 2259d, last: 2083d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in nmi_cpu_backtrace fs 7 2115d 2113d 0/26 auto-closed as invalid on 2019/02/22 10:26
upstream INFO: task hung in nmi_cpu_backtrace (2) serial 1 192d 192d 0/26 auto-obsoleted due to no activity on 2024/01/08 02:36
linux-4.14 INFO: task hung in nmi_cpu_backtrace 1 1568d 1568d 0/1 auto-closed as invalid on 2020/05/02 01:19

Sample crash report:
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
INFO: task syz-executor0:11276 blocked for more than 140 seconds.
__find_get_block_slow() failed. block=2, b_blocknr=8
      Not tainted 4.9.117-g8b21e85 #19
b_state=0x00000029, b_size=512
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
device loop0 blocksize: 2048
syz-executor0   D
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
28904 11276   7529 0x00000004
b_state=0x00000029, b_size=512
 ffff8801a0fd0000
device loop0 blocksize: 2048
 ffff8801c7eeef40 ffff8801c7eeef40 ffff8801c5e20000__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
 ffff8801db321c18
device loop0 blocksize: 2048
 ffff88019d9d76c8 ffffffff839ebd0d__find_get_block_slow() failed. block=2, b_blocknr=8
 dffffc0000000000b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
 ffff8801b74be110 ffff88019d9d7688
__find_get_block_slow() failed. block=2, b_blocknr=8
 00ff8801a0fd08c0b_state=0x00000029, b_size=512
 ffff8801db3224e8
device loop0 blocksize: 2048
 [<ffffffff839ed30f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff815c8102>] d_wait_lookup fs/dcache.c:2455 [inline]
 [<ffffffff815c8102>] d_alloc_parallel+0xeb2/0x17c0 fs/dcache.c:2537
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff8159b3da>] lookup_open+0x4ba/0x1930 fs/namei.c:3134
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
 [<ffffffff815a5ad3>] do_last fs/namei.c:3315 [inline]
 [<ffffffff815a5ad3>] path_openat+0x1803/0x3590 fs/namei.c:3534
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff815abb27>] do_filp_open+0x197/0x270 fs/namei.c:3568
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
 [<ffffffff8156e2fd>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff8156e5dd>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff8156e5dd>] SyS_open+0x2d/0x40 fs/open.c:1085
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff839fcc13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
b_state=0x00000029, b_size=512

Showing all locks held in the system:
device loop0 blocksize: 2048
2 locks held by khungtaskd/519:
__find_get_block_slow() failed. block=2, b_blocknr=8
 #0: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 2048
rcu_read_lock){......}__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff813667fc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
, at: [<ffffffff813667fc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1: 
device loop0 blocksize: 2048
 (tasklist_lock){.+.+..}__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff81426017>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
1 lock held by rsyslogd/3675:
device loop0 blocksize: 2048
 #0:  (&f->f_pos_lock
__find_get_block_slow() failed. block=2, b_blocknr=8
){+.+.+.}b_state=0x00000029, b_size=512
, at: [<ffffffff815d859c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3771:
 #0: 
__find_get_block_slow() failed. block=2, b_blocknr=8
 (b_state=0x00000029, b_size=512
&tty->ldisc_semdevice loop0 blocksize: 2048
){++++++}, at: [<ffffffff839fadb2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1: 
b_state=0x00000029, b_size=512
 (device loop0 blocksize: 2048
&ldata->atomic_read_lock){+.+...}, at: [<ffffffff821207f2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
b_state=0x00000029, b_size=512
1 lock held by syz-executor0/11276:
device loop0 blocksize: 2048
 #0:  (&sb->s_type->i_mutex_key
__find_get_block_slow() failed. block=2, b_blocknr=8
#15b_state=0x00000029, b_size=512
){++++++}device loop0 blocksize: 2048
, at: [<ffffffff815a5aac>] inode_lock_shared include/linux/fs.h:776 [inline]
, at: [<ffffffff815a5aac>] do_last fs/namei.c:3314 [inline]
, at: [<ffffffff815a5aac>] path_openat+0x17dc/0x3590 fs/namei.c:3534
2 locks held by syz-executor0/11281:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 2048
 (sb_writers#10__find_get_block_slow() failed. block=2, b_blocknr=8
){.+.+.+}b_state=0x00000029, b_size=512
, at: [<ffffffff815e0e3f>] sb_start_write include/linux/fs.h:1573 [inline]
, at: [<ffffffff815e0e3f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key
__find_get_block_slow() failed. block=2, b_blocknr=8
#15b_state=0x00000029, b_size=512
){++++++}device loop0 blocksize: 2048
, at: [<ffffffff815a51a5>] inode_lock include/linux/fs.h:766 [inline]
, at: [<ffffffff815a51a5>] do_last fs/namei.c:3312 [inline]
, at: [<ffffffff815a51a5>] path_openat+0xed5/0x3590 fs/namei.c:3534
1 lock held by init/11672:
b_state=0x00000029, b_size=512
 #0: 
device loop0 blocksize: 2048
 (tty_mutex){+.+.+.}__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff8211abfc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abfc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/11673:
device loop0 blocksize: 2048
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff8211abfc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abfc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/11674:
device loop0 blocksize: 2048
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff8211abfc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abfc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/11675:
device loop0 blocksize: 2048
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff8211abfc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abfc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125
1 lock held by init/11676:
device loop0 blocksize: 2048
 #0:  (tty_mutex){+.+.+.}
__find_get_block_slow() failed. block=2, b_blocknr=8
, at: [<ffffffff8211abfc>] tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
, at: [<ffffffff8211abfc>] tty_open+0x46c/0xe20 drivers/tty/tty_io.c:2125

device loop0 blocksize: 2048
=============================================

NMI backtrace for cpu 0
__find_get_block_slow() failed. block=2, b_blocknr=8
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.117-g8b21e85 #19
b_state=0x00000029, b_size=512
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
device loop0 blocksize: 2048
 ffff8801d86c7d08 ffffffff81eb4be9 0000000000000000
__find_get_block_slow() failed. block=2, b_blocknr=8
 0000000000000000b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
 0000000000000000 0000000000000001 ffffffff810b9bd0
__find_get_block_slow() failed. block=2, b_blocknr=8
 ffff8801d86c7d40b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
 ffffffff81ebfee7 0000000000000000 0000000000000000
__find_get_block_slow() failed. block=2, b_blocknr=8
 0000000000000003b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
Call Trace:
 [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
 [<ffffffff81ebfee7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff81ebfe7a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
b_state=0x00000029, b_size=512
 [<ffffffff810b9cd4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
device loop0 blocksize: 2048
 [<ffffffff81366d94>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366d94>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366d94>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366d94>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
 [<ffffffff8119d0ed>] kthread+0x26d/0x300 kernel/kthread.c:211
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
 [<ffffffff839fcddc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
b_state=0x00000029, b_size=512
Sending NMI from CPU 0 to CPUs 1:
device loop0 blocksize: 2048
NMI backtrace for cpu 1
CPU: 1 PID: 11269 Comm: syz-executor0 Not tainted 4.9.117-g8b21e85 #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801a94dc800 task.stack: ffff88019adc8000
RIP: 0010:[<ffffffff812355e2>] c [<ffffffff812355e2>] mark_held_locks+0x22/0x130 kernel/locking/lockdep.c:2643
RSP: 0018:ffff88019adcf1b8  EFLAGS: 00000096
RAX: ffff8801a94dd0c0 RBX: ffff8801a94dc800 RCX: 0000000000000000
RDX: 1ffff1003529ba18 RSI: 0000000000000000 RDI: ffff8801a94dc800
RBP: ffff88019adcf1f8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8125f477
R13: 000000000000001c R14: ffff8801a94dc800 R15: ffffffff85aec660
FS:  00007fc288b75700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f310ba04a30 CR3: 00000001cd34c000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff85aef0cac ffff88019adcf228c ffffffff8125a3e8c ffff8801a94dc800c
 ffffffff8125f477c 000000000000001cc 0000000000000002c ffffffff85aec660c
 ffff88019adcf218c ffffffff81235956c 0000000000000004c 000000000000001cc
Call Trace:
 [<ffffffff81235956>] __trace_hardirqs_on_caller kernel/locking/lockdep.c:2681 [inline]
 [<ffffffff81235956>] trace_hardirqs_on_caller+0x266/0x590 kernel/locking/lockdep.c:2736
 [<ffffffff81235c8d>] trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2743
 [<ffffffff8125f477>] vprintk_emit+0x257/0x790 kernel/printk/printk.c:1892
 [<ffffffff8125f9d8>] vprintk+0x28/0x30 kernel/printk/printk.c:1913
 [<ffffffff8125f9fd>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1914
 [<ffffffff8142cdec>] vprintk_func kernel/printk/internal.h:36 [inline]
 [<ffffffff8142cdec>] printk+0xaf/0xd7 kernel/printk/printk.c:1975
 [<ffffffff81cbac90>] __find_get_block_slow.cold.57+0xcd/0xf0 fs/buffer.c:244
 [<ffffffff8162493e>] __find_get_block+0x23e/0x4c0 fs/buffer.c:1360
 [<ffffffff81625749>] __getblk_slow fs/buffer.c:1101 [inline]
 [<ffffffff81625749>] __getblk_gfp+0x189/0x710 fs/buffer.c:1386
 [<ffffffff816290ed>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818b7908>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818b7908>] fat__get_entry+0x4c8/0x8f0 fs/fat/dir.c:100
 [<ffffffff818ba591>] fat_get_entry fs/fat/dir.c:128 [inline]
 [<ffffffff818ba591>] fat_get_short_entry+0x131/0x2a0 fs/fat/dir.c:876
 [<ffffffff818baaed>] fat_scan+0xfd/0x340 fs/fat/dir.c:961
 [<ffffffff818e21d9>] msdos_find+0xf9/0x2d0 fs/fat/namei_msdos.c:128
 [<ffffffff818e2af5>] msdos_lookup+0x135/0x250 fs/fat/namei_msdos.c:208
 [<ffffffff8159b55d>] lookup_open+0x63d/0x1930 fs/namei.c:3203
 [<ffffffff815a5ad3>] do_last fs/namei.c:3315 [inline]
 [<ffffffff815a5ad3>] path_openat+0x1803/0x3590 fs/namei.c:3534
 [<ffffffff815abb27>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8156e2fd>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8156e620>] SYSC_openat fs/open.c:1099 [inline]
 [<ffffffff8156e620>] SyS_openat+0x30/0x40 fs/open.c:1093
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fcc13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: c30 c00 ce9 cd7 cfa cff cff c66 c90 c55 c48 c8d c87 cc0 c08 c00 c00 c48 c89 ce5 c48 c89 cc2 c41 c57 c41 c56 c48 cc1 cea c03 c49 c89 cfe c41 c55 c41 c54 c53 c48 c83 cec c18 c<48> c89 c45 cc8 c48 cb8 c00 c00 c00 c00 c00 cfc cff cdf c0f cb6 c04 c02 c84 cc0 c74 c
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 2048
__find_get_block_slow() failed. block=2, b_blocknr=8

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/08/06 04:26 https://android.googlesource.com/kernel/common android-4.9 8b21e85d919c 1beb8136 .config console log report ci-android-49-kasan-gce-root
2018/04/26 11:18 https://android.googlesource.com/kernel/common android-4.9 132f097f6547 73417389 .config console log report ci-android-49-kasan-gce-root
2018/02/10 17:46 https://android.googlesource.com/kernel/common android-4.9 8a174b4749d3 e67d44e0 .config console log report ci-android-49-kasan-gce
* Struck through repros no longer work on HEAD.