syzbot


INFO: task hung in vfs_unlink

Status: auto-closed as invalid on 2020/05/28 17:30
Reported-by: syzbot+f1821c8f6291064572c8@syzkaller.appspotmail.com
First crash: 1665d, last: 1540d
Similar bugs (13)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in vfs_unlink (3) 2 18d 30d 0/3 upstream: reported on 2024/03/19 12:40
linux-6.1 INFO: task hung in vfs_unlink (2) 1 147d 147d 0/3 auto-obsoleted due to no activity on 2024/03/02 11:45
linux-4.14 INFO: task hung in vfs_unlink (2) 1 1095d 1095d 0/1 auto-closed as invalid on 2021/08/17 05:41
linux-4.14 INFO: task hung in vfs_unlink 8 1340d 1582d 0/1 auto-closed as invalid on 2020/12/15 00:37
linux-4.19 INFO: task hung in vfs_unlink (4) 1 526d 526d 0/1 auto-obsoleted due to no activity on 2023/03/09 01:26
linux-4.19 INFO: task hung in vfs_unlink (2) 2 1349d 1411d 0/1 auto-closed as invalid on 2020/12/05 18:54
upstream INFO: task hung in vfs_unlink (3) ext4 1 444d 444d 0/26 auto-obsoleted due to no activity on 2023/04/30 04:19
linux-5.15 INFO: task hung in vfs_unlink 29 31d 388d 0/3 upstream: reported on 2023/03/26 16:46
upstream INFO: task hung in vfs_unlink ext4 32 1362d 1639d 0/26 auto-closed as invalid on 2020/11/23 01:14
linux-6.1 INFO: task hung in vfs_unlink 2 336d 347d 0/3 auto-obsoleted due to no activity on 2023/08/26 02:49
linux-4.19 INFO: task hung in vfs_unlink (3) 1 988d 988d 0/1 auto-closed as invalid on 2021/12/01 23:35
upstream INFO: task hung in vfs_unlink (4) fs 6 183d 343d 0/26 auto-obsoleted due to no activity on 2024/01/16 15:08
upstream INFO: task hung in vfs_unlink (2) fs 1 621d 621d 0/26 auto-closed as invalid on 2022/10/05 08:13

Sample crash report:
libceph: mon0 [d::]:6789 connect error
libceph: connect [d::]:6789 error -101
libceph: mon0 [d::]:6789 connect error
NOHZ: local_softirq_pending 08
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
INFO: task syz-executor.4:8173 blocked for more than 140 seconds.
      Not tainted 4.19.100-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D23592  8173      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
 rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618
 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+0x53/0x90 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:747 [inline]
 vfs_unlink+0xd1/0x500 fs/namei.c:3993
 do_unlinkat+0x3f7/0x6d0 fs/namei.c:4065
 __do_sys_unlink fs/namei.c:4112 [inline]
 __se_sys_unlink fs/namei.c:4110 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4110
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b097
Code: 00 66 90 b8 58 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 2d b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcca688b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045b097
RDX: 00007ffcca688b50 RSI: 00007ffcca688b50 RDI: 00007ffcca688be0
RBP: 0000000000001221 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000003 R11: 0000000000000246 R12: 00007ffcca689c70
R13: 0000000001070940 R14: 0000000000000000 R15: 00007ffcca689c70

Showing all locks held in the system:
1 lock held by khungtaskd/1076:
 #0: 0000000029b5b89f (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
1 lock held by rsyslogd/7999:
 #0: 00000000326223a5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/8121:
 #0: 00000000bac81dd0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000467cfc63 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8122:
 #0: 00000000c678a8e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000add59a45 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8123:
 #0: 00000000c0ee265a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000668ac99d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8124:
 #0: 000000005b27a9e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000078d39858 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8125:
 #0: 00000000be4ecbc2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000c6ed32ac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8126:
 #0: 0000000006e4cc5c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000053701d87 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8127:
 #0: 000000007510e35c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000af7c0b2a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
3 locks held by syz-executor.4/8173:
 #0: 00000000d7bcb104 (sb_writers#4){.+.+}, at: sb_start_write include/linux/fs.h:1578 [inline]
 #0: 00000000d7bcb104 (sb_writers#4){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 #1: 0000000088fa3a0c (&type->i_mutex_dir_key#3/1){+.+.}, at: inode_lock_nested include/linux/fs.h:782 [inline]
 #1: 0000000088fa3a0c (&type->i_mutex_dir_key#3/1){+.+.}, at: do_unlinkat+0x29f/0x6d0 fs/namei.c:4051
 #2: 00000000af56c3f5 (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock include/linux/fs.h:747 [inline]
 #2: 00000000af56c3f5 (&sb->s_type->i_mutex_key#9){++++}, at: vfs_unlink+0xd1/0x500 fs/namei.c:3993
2 locks held by syz-executor.4/16403:
 #0: 00000000d7bcb104 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2775 [inline]
 #0: 00000000d7bcb104 (sb_writers#4){.+.+}, at: vfs_write+0x429/0x560 fs/read_write.c:548
 #1: 00000000af56c3f5 (&sb->s_type->i_mutex_key#9){++++}, at: inode_trylock include/linux/fs.h:767 [inline]
 #1: 00000000af56c3f5 (&sb->s_type->i_mutex_key#9){++++}, at: ext4_file_write_iter+0x23f/0x1060 fs/ext4/file.c:236

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

NMI backtrace for cpu 0
CPU: 0 PID: 1076 Comm: khungtaskd Not tainted 4.19.100-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 747 Comm: kworker/u4:4 Not tainted 4.19.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:97
Code: ff ff e8 83 63 ea ff 48 c7 05 44 e7 5d 09 00 00 00 00 e9 96 e9 ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 <48> 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 28 e9 96 7e 81 e2
RSP: 0018:ffff8880a8647bd0 EFLAGS: 00000282
RAX: ffff8880a8636600 RBX: 0000000000023980 RCX: ffffffff87380752
RDX: 0000000000000000 RSI: ffffffff87eafac0 RDI: ffffffff87eafb00
RBP: ffff8880a8647bd0 R08: ffff8880a8636600 R09: 0000000000000002
R10: ffff8880a8636ed0 R11: 00000000cec0425d R12: ffffffff87eafb00
R13: ffff88804bb86880 R14: ffffffff87eafac0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c421e48f00 CR3: 000000008b166000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 check_preemption_disabled+0x1c/0x290 lib/smp_processor_id.c:13
 debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:56
 rcu_dynticks_curr_cpu_in_eqs+0x17/0xb0 kernel/rcu/tree.c:348
 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:1025
 rcu_read_lock include/linux/rcupdate.h:628 [inline]
 batadv_nc_process_nc_paths.part.0+0x2c6/0x3c0 net/batman-adv/network-coding.c:698
 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:690 [inline]
 batadv_nc_worker+0x550/0x760 net/batman-adv/network-coding.c:739
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/29 17:30 linux-4.19.y 7cdefde351b6 5ed23f9a .config console log report ci2-linux-4-19
2019/12/24 11:23 linux-4.19.y 672481c2deff be5c2c81 .config console log report ci2-linux-4-19
2019/12/23 12:02 linux-4.19.y 672481c2deff be5c2c81 .config console log report ci2-linux-4-19
2019/12/16 23:17 linux-4.19.y 312017a460d5 0ae38e44 .config console log report ci2-linux-4-19
2019/10/08 19:58 linux-4.19.y 58fce2064530 b1ebbfef .config console log report ci2-linux-4-19
2019/09/27 01:11 linux-4.19.y d573e8a79f70 2f1548bc .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.