syzbot


INFO: task hung in do_truncate (2)

Status: auto-obsoleted due to no activity on 2023/11/27 08:00
Reported-by: syzbot+25c76ba42ecfe2237012@syzkaller.appspotmail.com
First crash: 240d, last: 240d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in do_truncate 1 392d 392d 0/3 auto-obsoleted due to no activity on 2023/07/17 23:13
upstream INFO: task hung in do_truncate (2) fs C done done 14 83d 1404d 0/26 upstream: reported C repro on 2020/06/11 04:48
upstream INFO: task hung in do_truncate ext4 C 7 1977d 2141d 0/26 closed as dup on 2018/09/08 15:38

Sample crash report:
INFO: task syz-executor.0:4433 blocked for more than 143 seconds.
      Not tainted 5.15.127-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:    0 pid: 4433 ppid:  4005 flags:0x00000005
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0xf10/0x1e38 kernel/sched/core.c:6372
 schedule+0x11c/0x1c8 kernel/sched/core.c:6455
 rwsem_down_write_slowpath+0xca8/0x1340 kernel/locking/rwsem.c:1157
 __down_write_common kernel/locking/rwsem.c:1284 [inline]
 __down_write kernel/locking/rwsem.c:1293 [inline]
 down_write+0x25c/0x260 kernel/locking/rwsem.c:1542
 inode_lock include/linux/fs.h:787 [inline]
 do_truncate+0x1ac/0x28c fs/open.c:63
 handle_truncate fs/namei.c:3195 [inline]
 do_open fs/namei.c:3542 [inline]
 path_openat+0x20e8/0x26f0 fs/namei.c:3672
 do_filp_open+0x1a8/0x3b4 fs/namei.c:3699
 do_sys_openat2+0x128/0x3d8 fs/open.c:1211
 do_sys_open fs/open.c:1227 [inline]
 __do_sys_openat fs/open.c:1243 [inline]
 __se_sys_openat fs/open.c:1238 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1238
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014ad1a20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
2 locks held by kworker/u4:2/148:
1 lock held by udevd/3586:
2 locks held by getty/3723:
 #0: ffff0000d3ba3098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001a2fe2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
1 lock held by syz-executor.1/4037:
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:475 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1621 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x328/0x1e38 kernel/sched/core.c:6286
2 locks held by syz-executor.0/4433:
 #0: ffff0000c0d98460 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377
 #1: ffff0000df706380 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000df706380 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: do_truncate+0x1ac/0x28c fs/open.c:63
3 locks held by syz-executor.0/4434:
2 locks held by syz-executor.0/8037:
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:475 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1621 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x328/0x1e38 kernel/sched/core.c:6286
 #1: ffff0001b4817c48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x438/0x66c kernel/sched/psi.c:891
4 locks held by syz-executor.4/8046:
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:475 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1621 [inline]
 #0: ffff0001b4829d18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x328/0x1e38 kernel/sched/core.c:6286
 #1: ffff0001b4817c48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x438/0x66c kernel/sched/psi.c:891
 #2: ffff0000c2acbf98 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0xc2c kernel/sched/core.c:4026
 #3: ffff800014ac7d98 (console_owner_lock){....}-{2:2}, at: console_lock_spinning_disable_and_check+0x28/0xc4 kernel/printk/printk.c:1827

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/19 07:59 linux-5.15.y f6f7927ac664 d216d8a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in do_truncate
* Struck through repros no longer work on HEAD.