syzbot


INFO: task hung in blk_trace_setup

Status: auto-closed as invalid on 2019/09/10 19:17
Subsystems: trace block
[Documentation on labels]
First crash: 1868d, last: 1868d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in blk_trace_setup (2) block trace 1 1496d 1496d 0/26 auto-closed as invalid on 2020/06/18 13:53

Sample crash report:
INFO: task syz-executor.4:6164 blocked for more than 143 seconds.
      Not tainted 5.0.0+ #21
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28368  6164  12381 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2877 [inline]
 __schedule+0x817/0x1cc0 kernel/sched/core.c:3518
 schedule+0x92/0x180 kernel/sched/core.c:3562
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 blk_trace_setup+0x3b/0x70 kernel/trace/blktrace.c:594
 sg_ioctl+0x369/0x2a10 drivers/scsi/sg.c:1117
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458079
Code: Bad RIP value.
RSP: 002b:00007f3f7fe9ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458079
RDX: 0000000020000000 RSI: 00000000c0481273 RDI: 0000000000000005
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3f7fe9b6d4
R13: 00000000004bf471 R14: 00000000004d0eb0 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by init/1:
 #0: 0000000023bbb0ba (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
1 lock held by khungtaskd/1039:
 #0: 0000000051826688 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061
3 locks held by udevd/3874:
1 lock held by rsyslogd/7829:
 #0: 000000008b69195e (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
1 lock held by cron/7868:
 #0: 000000008b69195e (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
2 locks held by getty/7918:
 #0: 00000000f97b7fc4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000002b6cae71 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7919:
 #0: 000000001cbb704d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000d6f9b344 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7920:
 #0: 0000000042522f8c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000c8551e67 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7921:
 #0: 0000000063879fe9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000001505bf66 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7922:
 #0: 0000000097a4eb87 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000045d34bf0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7923:
 #0: 00000000ad09c629 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000cf8430aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7924:
 #0: 00000000f6d232fa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000775cd4b1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
1 lock held by syz-fuzzer/7938:
 #0: 0000000093f5e00b (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
1 lock held by syz-fuzzer/7949:
 #0: 0000000093f5e00b (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
1 lock held by syz-executor.2/7960:
 #0: 00000000f3cdf467 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
1 lock held by syz-executor.4/12381:
 #0: 00000000f3cdf467 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308
2 locks held by syz-executor.2/5989:
1 lock held by syz-executor.4/6164:
 #0: 00000000d8347b0d (&q->blk_trace_mutex){+.+.}, at: blk_trace_setup+0x3b/0x70 kernel/trace/blktrace.c:594

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1039 Comm: khungtaskd Not tainted 5.0.0+ #21
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+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:204 [inline]
 watchdog+0x9b7/0xec0 kernel/hung_task.c:288
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/03/14 17:04 upstream fa3d493f7a57 d09a902e .config console log report ci-upstream-kasan-gce-root
* Struck through repros no longer work on HEAD.