syzbot


INFO: task hung in xfs_ilock (2)

Status: upstream: reported on 2025/03/22 05:42
Reported-by: syzbot+241ffda03886fa32f7fa@syzkaller.appspotmail.com
First crash: 15d, last: 15d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in xfs_ilock 1 305d 305d 0/3 auto-obsoleted due to no activity on 2024/09/13 20:46
linux-5.15 INFO: task hung in xfs_ilock (2) 3 13d 14d 0/3 upstream: reported on 2025/03/23 18:21
linux-5.15 INFO: task hung in xfs_ilock 1 305d 305d 0/3 auto-obsoleted due to no activity on 2024/09/13 19:01
upstream INFO: task hung in xfs_ilock xfs 7 473d 511d 0/28 auto-obsoleted due to no activity on 2024/03/20 00:19
upstream INFO: task hung in xfs_ilock (2) xfs 1 329d 329d 0/28 auto-obsoleted due to no activity on 2024/08/10 18:33

Sample crash report:
INFO: task syz.5.580:6606 blocked for more than 144 seconds.
      Not tainted 6.1.131-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.580       state:D stack:24728 pid:6606  ppid:6146   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6695
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline]
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read_nested+0x703/0xa40 kernel/locking/rwsem.c:1646
 xfs_ilock+0x1e6/0x430 fs/xfs/xfs_inode.c:206
 xfs_ilock_for_write_fault fs/xfs/xfs_file.c:244 [inline]
 __xfs_filemap_fault+0x3d6/0xb50 fs/xfs/xfs_file.c:1363
 do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:3011
 wp_page_shared+0x164/0x380 mm/memory.c:3360
 handle_pte_fault mm/memory.c:5049 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x2525/0x5340 mm/memory.c:5294
 faultin_page mm/gup.c:1026 [inline]
 __get_user_pages+0x4f3/0x1190 mm/gup.c:1250
 faultin_vma_page_range+0x21b/0x2b0 mm/gup.c:1670
 madvise_populate mm/madvise.c:928 [inline]
 madvise_vma_behavior mm/madvise.c:1037 [inline]
 madvise_walk_vmas mm/madvise.c:1259 [inline]
 do_madvise+0x16be/0x4480 mm/madvise.c:1438
 __do_sys_madvise mm/madvise.c:1451 [inline]
 __se_sys_madvise mm/madvise.c:1449 [inline]
 __x64_sys_madvise+0xa1/0xb0 mm/madvise.c:1449
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f430a38d169
RSP: 002b:00007f430b265038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007f430a5a6080 RCX: 00007f430a38d169
RDX: 0000000000000017 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f430a40e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f430a5a6080 R15: 00007fff7950c198
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32e890 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: 
ffffffff8d32f090
 (
rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
3 locks held by kworker/u4:4/75:
 #0: ffff8881401ef938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90001597d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: 
ffff88807614e0e0
 (
&type->s_umount_key#91){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:415
2 locks held by getty/4008:
 #0: ffff888030b29098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:7/4340:
 #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc900045c7d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
3 locks held by kworker/u4:8/4354:
 #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90004677d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e543a50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594
5 locks held by syz.5.580/6580:
 #0: ffff88807614e460 (sb_writers#25){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3015 [inline]
 #0: ffff88807614e460 (sb_writers#25){.+.+}-{0:0}, at: vfs_fallocate+0x4ba/0x6b0 fs/open.c:322
 #1: ffff888055e51a78 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: xfs_ilock+0x112/0x430 fs/xfs/xfs_inode.c:195
 #2: ffff888055e51c18 (mapping.invalidate_lock#11){++++}-{3:3}, at: xfs_ilock+0x1a3/0x430 fs/xfs/xfs_inode.c:203
 #3: ffff88807614e650 (sb_internal#4){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x263/0x12f0 fs/xfs/libxfs/xfs_bmap.c:4507
 #4: ffff888055e51858 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x291/0x12f0 fs/xfs/libxfs/xfs_bmap.c:4512
3 locks held by syz.5.580/6606:
 #0: ffff888077eb1058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
 #0: ffff888077eb1058 (&mm->mmap_lock){++++}-{3:3}, at: do_madvise+0x41a/0x4480 mm/madvise.c:1434
 #1: ffff88807614e558 (sb_pagefaults#3){.+.+}-{0:0}, at: do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:3011
 #2: ffff888055e51c18 (mapping.invalidate_lock#11){++++}-{3:3}, at: xfs_ilock+0x1e6/0x430 fs/xfs/xfs_inode.c:206
3 locks held by kworker/u4:28/7042:
 #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc9000c70fd20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: 
ffffffff8d333cf8
 (
rcu_state.exp_mutex
){+.+.}-{3:3}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
1 lock held by syz.3.890/8028:
 #0: 
ffffffff8d333cf8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
ffffffff8d333cf8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: xfs-buf/loop5 xfs_buf_ioend_work
RIP: 0010:io_serial_out+0x7a/0xb0 drivers/tty/serial/8250/8250_port.c:468
Code: fc 89 e9 41 d3 e7 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 90 e7 24 fd 44 03 3b 44 89 f0 44 89 fa ee <5b> 41 5c 41 5e 41 5f 5d c3 89 e9 80 e1 07 38 c1 7c ab 48 89 ef e8
RSP: 0018:ffffc900000c7230 EFLAGS: 00000002
RAX: 0000000000000036 RBX: ffffffff97747820 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff84bd2347 R09: ffffed10048d6047
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000036 R15: 00000000000003f8
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c2ff79178 CR3: 000000007f9a7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 serial8250_console_write+0x121c/0x1a30 drivers/tty/serial/8250/8250_port.c:3474
 call_console_driver kernel/printk/printk.c:1977 [inline]
 console_emit_next_record+0x86d/0xc30 kernel/printk/printk.c:2777
 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906
 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303
 _printk+0xd1/0x111 kernel/printk/printk.c:2328
 print_hex_dump+0x1a2/0x250 lib/hexdump.c:285
 xfs_hex_dump+0x39/0x50 fs/xfs/xfs_message.c:110
 xfs_buf_verifier_error+0x1ca/0x2a0 fs/xfs/xfs_error.c:441
 xfs_agf_read_verify+0x1f8/0x2a0 fs/xfs/libxfs/xfs_alloc.c:3029
 xfs_buf_ioend+0x28f/0x780 fs/xfs/xfs_buf.c:1303
 process_one_work+0x917/0x1260 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/22 07:49 linux-6.1.y 344a09659766 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in xfs_ilock
2025/03/22 08:03 linux-6.1.y 344a09659766 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in xfs_ilock
2025/03/22 05:41 linux-6.1.y 344a09659766 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in xfs_ilock
* Struck through repros no longer work on HEAD.