syzbot


INFO: task hung in mount_bdev (2)

Status: auto-closed as invalid on 2020/07/24 15:46
Reported-by: syzbot+b6fd3841dadd60f20c74@syzkaller.appspotmail.com
First crash: 825d, last: 825d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in mount_bdev 1 963d 963d 0/1 auto-closed as invalid on 2020/03/08 13:23
upstream INFO: task hung in mount_bdev 1 1293d 1293d 0/22 closed as dup on 2018/12/14 15:35
linux-4.14 INFO: task hung in mount_bdev (3) C 5 13d 557d 0/1 upstream: reported C repro on 2020/12/19 04:11
upstream INFO: task hung in mount_bdev (2) C done 1 1157d 1153d 0/22 closed as dup on 2019/05/03 10:52
linux-4.19 INFO: task hung in mount_bdev C error 3 267d 1042d 0/1 upstream: reported C repro on 2019/08/22 06:31

Sample crash report:
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task syz-executor.1:14457 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D29936 14457   7358 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x370 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x3c9/0x24f0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c849
RSP: 002b:00007fec69cffc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fec69d006d4 RCX: 000000000045c849
RDX: 0000000020000200 RSI: 0000000020000000 RDI: 0000000020000080
RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000749 R14: 00000000004ca11a R15: 000000000076c04c
INFO: task syz-executor.3:14415 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28992 14415   7359 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
 rwsem_down_write_failed+0x5c3/0xbb0 kernel/locking/rwsem-xadd.c:617
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:56
 grab_super+0x55/0x140 fs/super.c:373
 sget_userns+0x2b1/0xc30 fs/super.c:504
 sget+0xd1/0x110 fs/super.c:572
 mount_bdev+0xcd/0x370 fs/super.c:1107
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x3c9/0x24f0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45f29a
RSP: 002b:00007f484ed15a68 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f484ed166d4 RCX: 000000000045f29a
RDX: 00007f484ed15ae0 RSI: 0000000020000040 RDI: 00007f484ed15b00
RBP: 000000000076bf00 R08: 00007f484ed15b40 R09: 00007f484ed15ae0
R10: 0000000000000001 R11: 0000000000000206 R12: 00000000ffffffff
R13: 0000000000000be1 R14: 00000000004ce00d R15: 000000000076bf0c

Showing all locks held in the system:
1 lock held by khungtaskd/1056:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff81465b93>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544
2 locks held by getty/7310:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7311:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7312:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7313:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7314:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7315:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7316:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.1/14457:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff818bb791>] mount_bdev+0x71/0x370 fs/super.c:1101
2 locks held by syz-executor.3/14415:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff818bb791>] mount_bdev+0x71/0x370 fs/super.c:1101
 #1:  (&type->s_umount_key#68){+.+.}, at: [<ffffffff818b9cc5>] grab_super+0x55/0x140 fs/super.c:373

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

NMI backtrace for cpu 0
CPU: 0 PID: 1056 Comm: khungtaskd Not tainted 4.14.174-syzkaller #0
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+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e2/0xb80 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 14416 Comm: syz-executor.1 Not tainted 4.14.174-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888055dec440 task.stack: ffff88804ee48000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:362 [inline]
RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:1130
RSP: 0018:ffff88804ee4f988 EFLAGS: 00000a03
RAX: dffffc0000000000 RBX: ffff8880aeb23940 RCX: 1ffffffff0f417ad
RDX: 0000000000000000 RSI: ffffffff82fe2645 RDI: ffff8880aeb2394c
RBP: ffff88809622ebe8 R08: 0000000000000000 R09: 0000000000020012
R10: ffff888055decce8 R11: ffff888055dec440 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000008 R15: dffffc0000000000
FS:  00007fec69d42700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f24a6fac000 CR3: 00000000a0774000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_read_lock_held+0x7c/0xc0 kernel/rcu/update.c:328
 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
 find_get_entry+0x2ee/0x690 mm/filemap.c:1357
 pagecache_get_page+0x44/0xa10 mm/filemap.c:1465
 find_or_create_page include/linux/pagemap.h:326 [inline]
 grow_dev_page fs/buffer.c:1004 [inline]
 grow_buffers fs/buffer.c:1077 [inline]
 __getblk_slow fs/buffer.c:1104 [inline]
 __getblk_gfp+0x23d/0x7c0 fs/buffer.c:1383
 __bread_gfp+0x29/0x290 fs/buffer.c:1417
 sb_bread include/linux/buffer_head.h:307 [inline]
 isofs_fill_super+0x9c8/0x25a4 fs/isofs/inode.c:678
 mount_bdev+0x2bc/0x370 fs/super.c:1134
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x3c9/0x24f0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c849
RSP: 002b:00007fec69d41c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fec69d426d4 RCX: 000000000045c849
RDX: 0000000020000200 RSI: 0000000020000000 RDI: 0000000020000080
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000749 R14: 00000000004ca11a R15: 000000000076bf0c
Code: 48 c1 e9 03 80 3c 11 00 75 5b 48 03 1c c5 60 bd a0 87 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 0c 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 22 8b 43 0c d1 

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/03/26 15:45 linux-4.14.y 01364dad1d45 6d25c5a0 .config log report