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INFO: task hung in rwsem_down_read_failed

Status: closed as invalid on 2018/02/14 14:55
Subsystems: perf
[Documentation on labels]
Reported-by: syzbot+92cd172a6023d578d2bacacfec080a4f45529373@syzkaller.appspotmail.com
First crash: 2324d, last: 2273d
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in rwsem_down_read_failed C 10 2302d 1839d 0/2 public: reported C repro on 2019/04/13 00:00
android-49 INFO: task hung in rwsem_down_read_failed C 42 2304d 1839d 0/3 public: reported C repro on 2019/04/13 00:00

Sample crash report:
INFO: task syz-executor0:10244 blocked for more than 120 seconds.
      Not tainted 4.15.0-rc8+ #269
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D23984 10244   4352 0x80000004
Call Trace:
 context_switch kernel/sched/core.c:2799 [inline]
 __schedule+0x8eb/0x2060 kernel/sched/core.c:3375
 schedule+0xf5/0x430 kernel/sched/core.c:3434
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x401/0x6e0 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 down_read+0xa4/0x150 kernel/locking/rwsem.c:26
 exit_mm kernel/exit.c:510 [inline]
 do_exit+0x4b0/0x1ad0 kernel/exit.c:852
 do_group_exit+0x149/0x400 kernel/exit.c:968
 get_signal+0x73f/0x16c0 kernel/signal.c:2335
 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
 entry_SYSCALL_64_fastpath+0x9e/0xa0
RIP: 0033:0x452f3a
RSP: 002b:0000000000a2f728 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 0000000000452f3a
RDX: 0000000000000003 RSI: 0000000000021000 RDI: 0000000000000000
RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000020022 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000021000 R14: 0000000000020022 R15: 0000000000000000

Showing all locks held in the system:
2 locks held by khungtaskd/747:
 #0:  (rcu_read_lock){....}, at: [<0000000004fa58ff>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0:  (rcu_read_lock){....}, at: [<0000000004fa58ff>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
 #1:  (tasklist_lock){.+.+}, at: [<000000001b6e7282>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464
1 lock held by khugepaged/753:
 #0:  (&mm->mmap_sem){++++}, at: [<00000000dd448474>] khugepaged_scan_mm_slot mm/khugepaged.c:1677 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<00000000dd448474>] khugepaged_do_scan mm/khugepaged.c:1810 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<00000000dd448474>] khugepaged+0x9d8/0x1400 mm/khugepaged.c:1855
1 lock held by rsyslogd/3507:
 #0:  (&f->f_pos_lock){+.+.}, at: [<0000000004d518bb>] __fdget_pos+0x12b/0x190 fs/file.c:770
2 locks held by getty/3630:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/3631:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/3632:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/3633:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/3634:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/3635:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/3636:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000449960c6>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000b3dd5fa8>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
1 lock held by syz-executor0/10244:
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] exit_mm kernel/exit.c:510 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852
1 lock held by syz-executor0/10251:
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] exit_mm kernel/exit.c:510 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852
1 lock held by syz-executor0/10260:
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] exit_mm kernel/exit.c:510 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852
1 lock held by syz-executor0/10261:
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] exit_mm kernel/exit.c:510 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<000000000f953af0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852

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

NMI backtrace for cpu 1
CPU: 1 PID: 747 Comm: khungtaskd Not tainted 4.15.0-rc8+ #269
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+0x194/0x257 lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x122/0x180 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
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10258 Comm: syz-executor0 Not tainted 4.15.0-rc8+ #269
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:777 [inline]
RIP: 0010:lock_release+0x503/0xa40 kernel/locking/lockdep.c:3936
RSP: 0018:ffff8801c785f518 EFLAGS: 00000282
RAX: dffffc0000000000 RBX: ffff8801c93b6380 RCX: 1ffff10039276d7d
RDX: 1ffffffff0d1918d RSI: 0000000000000002 RDI: 0000000000000282
RBP: ffff8801c785f648 R08: 0000000000000000 R09: 1ffff10038f0beac
R10: ffff8801c785f7d8 R11: 0000000000000001 R12: b8125932a2befdb6
R13: ffff8801c93b6380 R14: ffff8801c785f560 R15: 1ffff10038f0bea8
FS:  00007efc7ed38700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002131218 CR3: 00000001bf718002 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 __mutex_unlock_slowpath+0xe9/0xac0 kernel/locking/mutex.c:1018
 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614
 perf_mmap+0x81f/0x1b70 kernel/events/core.c:5290
 call_mmap include/linux/fs.h:1777 [inline]
 mmap_region+0xa99/0x15a0 mm/mmap.c:1705
 do_mmap+0x6c0/0xe00 mm/mmap.c:1483
 do_mmap_pgoff include/linux/mm.h:2217 [inline]
 vm_mmap_pgoff+0x1de/0x280 mm/util.c:333
 SYSC_mmap_pgoff mm/mmap.c:1533 [inline]
 SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1491
 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ee9
RSP: 002b:00007efc7ed37c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 000000000071bf58 RCX: 0000000000452ee9
RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020f1f000
RBP: 00000000000003d6 R08: 0000000000000016 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000212 R12: 00000000006f4cb0
R13: 00000000ffffffff R14: 00007efc7ed386d4 R15: 0000000000000000
Code: 00 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 89 04 00 00 48 83 3d 64 46 36 05 00 0f 84 0d 02 00 00 48 8b bd e0 fe ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 49 c7 04 07 00 00

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/01/20 07:20 upstream ec835f8104a2 fbbdcd92 .config console log report ci-upstream-kasan-gce
2017/12/15 20:49 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce-386
2018/02/03 09:55 bpf-next b2fe5fa68642 632a8c2c .config console log report ci-upstream-bpf-next-kasan-gce
2018/02/01 08:05 bpf-next 868c36dcc949 02553e22 .config console log report ci-upstream-bpf-next-kasan-gce
2018/02/01 04:00 bpf-next 868c36dcc949 02553e22 .config console log report ci-upstream-bpf-next-kasan-gce
2018/01/29 01:50 bpf-next 8223967fe0b8 08d47756 .config console log report ci-upstream-bpf-next-kasan-gce
2018/01/24 04:46 bpf-next 2310035fa03f a5b7566c .config console log report ci-upstream-bpf-next-kasan-gce
2017/12/14 09:09 linux-next 6084b576dca2 ac20b98c .config console log report ci-upstream-next-kasan-gce
* Struck through repros no longer work on HEAD.