syzbot


INFO: task hung in ext4_punch_hole

Status: auto-obsoleted due to no activity on 2025/06/16 04:39
Subsystems: fs mm
[Documentation on labels]
First crash: 97d, last: 97d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in ext4_punch_hole 1 2461d 2461d 0/3 auto-closed as invalid on 2019/03/25 18:21

Sample crash report:
INFO: task syz.4.2898:12450 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc7-syzkaller-00050-gfc444ada1310 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2898      state:D stack:25840 pid:12450 tgid:12449 ppid:10273  task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 io_schedule+0xbf/0x130 kernel/sched/core.c:7690
 folio_wait_bit_common+0x3d8/0x9b0 mm/filemap.c:1317
 folio_wait_writeback+0x3c/0x90 mm/page-writeback.c:3179
 __filemap_fdatawait_range+0x123/0x210 mm/filemap.c:541
 filemap_write_and_wait_range mm/filemap.c:702 [inline]
 filemap_write_and_wait_range+0xeb/0x130 mm/filemap.c:684
 ext4_punch_hole+0x194/0x10d0 fs/ext4/inode.c:3964
 ext4_fallocate+0x9b7/0x3950 fs/ext4/extents.c:4772
 vfs_fallocate+0x60d/0x10d0 fs/open.c:338
 madvise_remove mm/madvise.c:1034 [inline]
 madvise_vma_behavior+0x1ae3/0x1de0 mm/madvise.c:1269
 madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1511
 do_madvise+0x366/0x7c0 mm/madvise.c:1698
 __do_sys_madvise mm/madvise.c:1714 [inline]
 __se_sys_madvise mm/madvise.c:1712 [inline]
 __x64_sys_madvise+0xa9/0x110 mm/madvise.c:1712
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd44338d169
RSP: 002b:00007fd4441f9038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007fd4435a5fa0 RCX: 00007fd44338d169
RDX: 0000000000000009 RSI: 00000000008031ca RDI: 000000110c230000
RBP: 00007fd44340e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd4435a5fa0 R15: 00007ffc1e7e3448
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
6 locks held by kworker/u8:3/54:
 #0: ffff88801f29d948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
 #1: ffffc90000bf7d18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
 #2: ffff88814e7e80e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562
 #3: ffff88814e7eab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b3/0x820 mm/page-writeback.c:2687
 #4: ffff88814e7ec950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448
 #5: ffff888078898c70 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x352/0x1370 fs/ext4/inode.c:701
3 locks held by syz-executor/5826:
 #0: ffff888026f89a90 (&vma->vm_lock->lock){++++}-{4:4}, at: vma_start_read include/linux/mm.h:717 [inline]
 #0: ffff888026f89a90 (&vma->vm_lock->lock){++++}-{4:4}, at: lock_vma_under_rcu+0x13e/0x980 mm/memory.c:6366
 #1: ffff88814e7e8518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x177/0x380 mm/memory.c:3256
 #2: ffff88814e7ec950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448
2 locks held by getty/12310:
 #0: ffff88814d20c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900030a52f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
1 lock held by syz.4.2898/12450:
 #0: ffff88814e7e8420 (sb_writers#4){.+.+}-{0:0}, at: madvise_remove mm/madvise.c:1034 [inline]
 #0: ffff88814e7e8420 (sb_writers#4){.+.+}-{0:0}, at: madvise_vma_behavior+0x1ae3/0x1de0 mm/madvise.c:1269
3 locks held by syz.3.2938/12543:
 #0: ffff888029d8e220 (&vma->vm_lock->lock){++++}-{4:4}, at: vma_start_read include/linux/mm.h:717 [inline]
 #0: ffff888029d8e220 (&vma->vm_lock->lock){++++}-{4:4}, at: lock_vma_under_rcu+0x13e/0x980 mm/memory.c:6366
 #1: ffff88814e7e8518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x177/0x380 mm/memory.c:3256
 #2: ffff88814e7ec950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448
3 locks held by syz.2.2939/12545:
 #0: ffff88805ef12148 (&vma->vm_lock->lock){++++}-{4:4}, at: vma_start_read include/linux/mm.h:717 [inline]
 #0: ffff88805ef12148 (&vma->vm_lock->lock){++++}-{4:4}, at: lock_vma_under_rcu+0x13e/0x980 mm/memory.c:6366
 #1: ffff88814e7e8518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x177/0x380 mm/memory.c:3256
 #2: ffff88814e7ec950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448
3 locks held by syz.5.2940/12547:
 #0: ffff88803238b658 (&vma->vm_lock->lock){++++}-{4:4}, at: vma_start_read include/linux/mm.h:717 [inline]
 #0: ffff88803238b658 (&vma->vm_lock->lock){++++}-{4:4}, at: lock_vma_under_rcu+0x13e/0x980 mm/memory.c:6366
 #1: ffff88814e7e8518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x177/0x380 mm/memory.c:3256
 #2: ffff88814e7ec950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc7-syzkaller-00050-gfc444ada1310 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0xf62/0x12b0 kernel/hung_task.c:399
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/18 04:32 upstream fc444ada1310 ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in ext4_punch_hole
* Struck through repros no longer work on HEAD.