INFO: task kworker/u4:12:4556 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:12 state:D stack:25264 pid:4556 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:102
jfs_write_inode+0x141/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1470 [inline]
__writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687
writeback_sb_inodes+0xad8/0x17d0 fs/fs-writeback.c:1913
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984
wb_writeback+0x47a/0xd00 fs/fs-writeback.c:2089
wb_check_background_flush fs/fs-writeback.c:2155 [inline]
wb_do_writeback fs/fs-writeback.c:2243 [inline]
wb_workfn+0xbdd/0xec0 fs/fs-writeback.c:2270
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
INFO: task syz.4.530:6350 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.530 state:D stack:24520 pid:6350 ppid:4271 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
io_schedule+0x7c/0xd0 kernel/sched/core.c:8797
folio_wait_bit_common+0x6e1/0xf60 mm/filemap.c:1324
release_metapage+0x93/0x980 fs/jfs/jfs_metapage.c:735
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa65/0xfa0 fs/jfs/jfs_metapage.c:644
dtSplitPage+0x77f/0x31d0 fs/jfs/jfs_dtree.c:1471
dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
dtInsert+0xfbd/0x58a0 fs/jfs/jfs_dtree.c:871
jfs_create+0x69d/0xa50 fs/jfs/namei.c:137
lookup_open fs/namei.c:3490 [inline]
open_last_lookups fs/namei.c:3558 [inline]
path_openat+0x1187/0x2e70 fs/namei.c:3788
do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
do_sys_openat2+0x142/0x490 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5828b8f6c9
RSP: 002b:00007f5829aca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5828de5fa0 RCX: 00007f5828b8f6c9
RDX: 0000000000105042 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f5828c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5828de6038 R14: 00007f5828de5fa0 R15: 00007ffff138dd58
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b630 (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: ffffffff8cb2be50 (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: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
1 lock held by syslogd/3619:
#0: ffff8880b8e3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545
1 lock held by dhcpcd/3932:
#0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xd5/0xcd0 net/netlink/af_netlink.c:2179
2 locks held by getty/4028:
#0: ffff88802f941098 (&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+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by kworker/u4:8/4376:
3 locks held by kworker/0:6/4392:
#0: ffff88802ed71538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900044f7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4672
2 locks held by kworker/0:7/4395:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004517d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
4 locks held by kworker/u4:12/4556:
#0: ffff888142e8a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900049dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff8880799760e0 (&type->s_umount_key#77){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
#3: ffff88807063b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:102
4 locks held by syz.4.530/6350:
#0: ffff888079976460 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
#1: ffff88807063bd00 (&type->i_mutex_dir_key#17){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#1: ffff88807063bd00 (&type->i_mutex_dir_key#17){++++}-{3:3}, at: open_last_lookups fs/namei.c:3555 [inline]
#1: ffff88807063bd00 (&type->i_mutex_dir_key#17){++++}-{3:3}, at: path_openat+0x7c2/0x2e70 fs/namei.c:3788
#2: ffff88807063b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_create+0x1ef/0xa50 fs/jfs/namei.c:100
#3: ffff88807063d508 (&jfs_ip->commit_mutex/1){+.+.}-{3:3}, at: jfs_create+0x20a/0xa50 fs/jfs/namei.c:101
2 locks held by syz.3.917/7843:
#0: ffff8880705ebe10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#0: ffff8880705ebe10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
#0: ffff8880705ebe10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400
#1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
4 locks held by syz.5.916/7852:
#0: ffff8880793be1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: __tty_hangup+0xbe/0x620 drivers/tty/tty_io.c:591
#1: ffff8880793be098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#1: ffff8880793be098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x68/0xb0 drivers/tty/tty_ldisc.c:314
#2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0x6f/0x1b0 net/core/dev.c:11048
#3: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#3: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
=============================================
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 10/02/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 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: 11 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:find_held_lock kernel/locking/lockdep.c:-1 [inline]
RIP: 0010:__lock_release kernel/locking/lockdep.c:5337 [inline]
RIP: 0010:lock_release+0x215/0x910 kernel/locking/lockdep.c:5682
Code: 89 44 24 28 83 f8 32 0f 83 e5 04 00 00 4b 8d 04 b6 4c 8d 24 c3 48 89 c3 4c 89 e7 48 8b 74 24 10 e8 60 5b b4 08 44 89 7c 24 3c <44> 89 fa 85 c0 0f 84 d9 01 00 00 4d 85 e4 0f 84 01 03 00 00 4d 8d
RSP: 0018:ffffc90000107ac0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 000000000000000a RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8cb2aca0 RDI: ffff88813fe746b0
RBP: ffffc90000107bd0 R08: dffffc0000000000 R09: fffffbfff1c3ed56
R10: fffffbfff1c3ed56 R11: 1ffffffff1c3ed55 R12: ffff88813fe746b0
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055892de06000 CR3: 000000007bbf6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_release include/linux/rcupdate.h:355 [inline]
rcu_read_unlock include/linux/rcupdate.h:824 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x28d/0x600 net/batman-adv/network-coding.c:719
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295