INFO: task syz-executor:4281 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22096 pid:4281 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
wb_wait_for_completion+0x16f/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x1c5/0xa10 fs/fs-writeback.c:2756
sync_filesystem+0x16d/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd68ef9e097
RSP: 002b:00007ffc97696248 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd68f0321ca RCX: 00007fd68ef9e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc97696300
RBP: 00007ffc97696300 R08: 00007ffc97697300 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc97697390
R13: 00007fd68f0321ca R14: 000000000001b050 R15: 00007ffc976973d0
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e7f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2f010 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:2/30:
2 locks held by kworker/1:2/125:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002da7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4027:
#0: ffff88814d53c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by syz-executor/4281:
#0: ffff8880778b00e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
#1: ffff8880248a07d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff8880248a07d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a9/0xa10 fs/fs-writeback.c:2754
4 locks held by kworker/u4:5/4306:
#0: ffff88801c25b138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90003fe7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2:
ffff8880778b0650
(
sb_internal
#2){++++}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline]
#2){++++}-{0:0}, at: xfs_bmapi_convert_delalloc+0x341/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698
#3: ffff888070622f98 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline]
#3: ffff888070622f98 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x368/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698
3 locks held by kworker/1:13/4810:
#0:
ffff88802f2a1138
((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1:
ffffc90005847d00
((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x14f0 net/ipv6/addrconf.c:4131
5 locks held by kworker/1:15/4813:
1 lock held by syz-executor/5074:
#0: ffffffff8cb33b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8cb33b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
4 locks held by kworker/u4:14/5643:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000352fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd3dd50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:594
#3: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0xc7/0x4a0 net/ipv6/ip6_gre.c:1674
3 locks held by kworker/u4:19/6213:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000bebfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
2 locks held by syz.2.663/6886:
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
#1: ffffffff8cb33b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb33b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
1 lock held by syz.1.660/6894:
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3fc/0x1e60 drivers/net/tun.c:3104
1 lock held by syz.1.660/6895:
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
1 lock held by syz.1.660/6897:
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x54d/0xe80 net/core/dev_ioctl.c:571
1 lock held by syz.3.665/6921:
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd4abe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6155
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4306 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:__sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:234
Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 34 f3 7f 7e 65 8b
RSP: 0018:ffffc90003fe5358 EFLAGS: 00000293
RAX: ffffffff8a206c5d RBX: 0000000000000001 RCX: ffff88807e79da00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90003fe5480 R08: ffffc90003fe53f7 R09: ffffc90003fe53e0
R10: dffffc0000000000 R11: fffff520007fca7f R12: ffffc90003fe5762
R13: 0000000000000003 R14: ffffc90003fe5762 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557d6264e8 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
number+0x4dd/0xf60 lib/vsprintf.c:519
vsnprintf+0x12d2/0x1c20 lib/vsprintf.c:2871
sprintf+0xe4/0x140 lib/vsprintf.c:3009
print_time kernel/printk/printk.c:1274 [inline]
info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300
record_print_text+0x173/0x440 kernel/printk/printk.c:1349
console_emit_next_record+0x598/0xba0 kernel/printk/printk.c:2760
console_flush_all kernel/printk/printk.c:-1 [inline]
console_unlock+0x223/0x630 kernel/printk/printk.c:2906
vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
_printk+0xda/0x130 kernel/printk/printk.c:2328
__xfs_printk fs/xfs/xfs_message.c:24 [inline]
xfs_buf_alert_ratelimited+0x243/0x250 fs/xfs/xfs_message.c:131
xfs_buf_ioerror_alert fs/xfs/xfs_buf.c:1378 [inline]
xfs_buf_read_map+0x58a/0xa10 fs/xfs/xfs_buf.c:860
xfs_trans_read_buf_map+0x1d8/0x9c0 fs/xfs/xfs_trans_buf.c:289
xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline]
xfs_btree_read_buf_block+0x1db/0x2d0 fs/xfs/libxfs/xfs_btree.c:1351
xfs_btree_lookup_get_block+0x282/0x650 fs/xfs/libxfs/xfs_btree.c:1822
xfs_btree_lookup+0x32d/0x1090 fs/xfs/libxfs/xfs_btree.c:1913
xfs_alloc_lookup_eq+0x5e/0x100 fs/xfs/libxfs/xfs_alloc.c:171
xfs_alloc_fixup_trees+0x11f/0x7f0 fs/xfs/libxfs/xfs_alloc.c:495
xfs_alloc_cur_finish+0xd3/0x500 fs/xfs/libxfs/xfs_alloc.c:946
xfs_alloc_ag_vextent_near+0xdd4/0x1360 fs/xfs/libxfs/xfs_alloc.c:1658
xfs_alloc_ag_vextent+0x94/0x7a0 fs/xfs/libxfs/xfs_alloc.c:1164
xfs_alloc_vextent+0xa47/0x1e90 fs/xfs/libxfs/xfs_alloc.c:3263
xfs_bmap_btalloc+0xffd/0x1e90 fs/xfs/libxfs/xfs_bmap.c:3662
xfs_bmapi_allocate+0x71e/0xf30 fs/xfs/libxfs/xfs_bmap.c:-1
xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4639 [inline]
xfs_bmapi_convert_delalloc+0x808/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698
xfs_map_blocks+0x990/0x1490 fs/xfs/xfs_aops.c:352
iomap_writepage_map fs/iomap/buffered-io.c:1619 [inline]
iomap_do_writepage+0x987/0x3080 fs/iomap/buffered-io.c:1785
write_cache_pages+0x892/0x1470 mm/page-writeback.c:2382
iomap_writepages+0x5a/0x210 fs/iomap/buffered-io.c:1802
xfs_vm_writepages+0x156/0x1d0 fs/xfs/xfs_aops.c:477
do_writepages+0x3ba/0x640 mm/page-writeback.c:2491
__writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622
writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913
wb_writeback+0x482/0xd50 fs/fs-writeback.c:2087
wb_do_writeback fs/fs-writeback.c:2230 [inline]
wb_workfn+0x423/0xee0 fs/fs-writeback.c:2270
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295