INFO: task kworker/u8:8:1374 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8 state:D stack:22360 pid:1374 tgid:1374 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:7)
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14de/0x5210 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
io_schedule+0x80/0xe0 kernel/sched/core.c:7831
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:375
jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75d/0x1060 fs/fs-writeback.c:1813
writeback_sb_inodes+0x92e/0x1910 fs/fs-writeback.c:2041
wb_writeback+0x445/0xad0 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x3fd/0xf00 fs/fs-writeback.c:2414
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.7.117:6826 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.117 state:D stack:25496 pid:6826 tgid:6825 ppid:6114 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14de/0x5210 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
wb_wait_for_completion+0x372/0x690 fs/fs-writeback.c:226
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2838
sync_filesystem+0xa2/0x250 fs/sync.c:54
jfs_reconfigure+0xc6/0xa00 fs/jfs/super.c:370
reconfigure_super+0x227/0x8a0 fs/super.c:1080
do_remount fs/namespace.c:3388 [inline]
path_mount+0xdc5/0x10e0 fs/namespace.c:4138
do_mount fs/namespace.c:4159 [inline]
__do_sys_mount fs/namespace.c:4348 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4325
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f14eae8d20a
RSP: 002b:00007f14e90e5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f14e90e5ee0 RCX: 00007f14eae8d20a
RDX: 00002000000003c0 RSI: 0000200000000340 RDI: 0000000000000000
RBP: 00002000000003c0 R08: 00007f14e90e5ee0 R09: 000000000126a4b5
R10: 000000000126a4b5 R11: 0000000000000246 R12: 0000200000000340
R13: 00007f14e90e5ea0 R14: 0000000000000000 R15: 0000200000004140
Showing all locks held in the system:
5 locks held by kworker/0:0/9:
#0: ffff88813fe3b538 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe3b538 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc900000e7c40 ((work_completion)(&br->mcast_gc_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc900000e7c40 ((work_completion)(&br->mcast_gc_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8da64ce0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#3: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#4: ffff888060911778 (&br->multicast_lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
#4: ffff888060911778 (&br->multicast_lock){+...}-{3:3}, at: br_multicast_gc_work+0x9d/0x260 net/bridge/br_multicast.c:4090
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/56:
2 locks held by kworker/u8:8/1374:
#0: ffff88801e6f9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801e6f9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc90004d57c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90004d57c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
3 locks held by kworker/u8:10/1381:
#0: ffff88803173e138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88803173e138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc90004e57c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90004e57c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194
1 lock held by syslogd/5147:
2 locks held by dhcpcd/5459:
#0: ffffffff8ef2f618 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x644/0x7f0 net/socket.c:1337
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xf0/0x630 net/8021q/vlan.c:579
2 locks held by getty/5561:
#0: ffff888036c900a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900042162e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
4 locks held by syz-executor/5785:
3 locks held by kworker/0:3/5787:
#0: ffff88813fe3bd38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe3bd38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc90004cc7c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90004cc7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz.7.117/6826:
#0: ffff88803b29e0d0 (&type->s_umount_key#69){++++}-{4:4}, at: do_remount fs/namespace.c:3385 [inline]
#0: ffff88803b29e0d0 (&type->s_umount_key#69){++++}-{4:4}, at: path_mount+0xd7d/0x10e0 fs/namespace.c:4138
1 lock held by udevd/6935:
#0: ffff888022282228 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff888022282228 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:855
11 locks held by kworker/u8:14/6967:
6 locks held by kworker/u8:15/7459:
1 lock held by syz.8.192/7612:
#0: ffff88803b29e0d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88803b29e0d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz-executor/8058:
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
2 locks held by syz-executor/8286:
#0: ffffffff8e6b91a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e6b91a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e6b91a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
1 lock held by syz.1.281/8321:
1 lock held by syz.0.284/8340:
#0: ffff88805b9f00d0 (&type->s_umount_key#55/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
2 locks held by syz.3.286/8349:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5785 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:check_preemption_disabled+0x3/0xe0 lib/smp_processor_id.c:13
Code: 86 8b 48 c7 c6 60 15 86 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 <41> 56 53 65 8b 05 47 43 16 07 65 8b 0d 3c 43 16 07 f7 c1 ff ff ff
RSP: 0018:ffffc90004c97538 EFLAGS: 00000283
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8b861560 RDI: ffffffff8b861520
RBP: ffffffff822b8ff0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff94000274fe7 R12: 0000000000000002
R13: ffffffff8dbcd480 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126695000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f563c473000 CR3: 0000000038152000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x330 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
lruvec_stat_mod_folio+0x8c/0x4b0 mm/memcontrol.c:797
__folio_mod_stat mm/rmap.c:1215 [inline]
__folio_remove_rmap mm/rmap.c:1752 [inline]
folio_remove_rmap_ptes+0x46e/0x7c0 mm/rmap.c:1779
zap_present_folio_ptes mm/memory.c:1654 [inline]
zap_present_ptes mm/memory.c:1712 [inline]
do_zap_pte_range mm/memory.c:1814 [inline]
zap_pte_range mm/memory.c:1858 [inline]
zap_pmd_range mm/memory.c:1950 [inline]
zap_pud_range mm/memory.c:1978 [inline]
zap_p4d_range mm/memory.c:1999 [inline]
unmap_page_range+0x1a8d/0x3cd0 mm/memory.c:2020
unmap_single_vma mm/memory.c:2062 [inline]
unmap_vmas+0x3c0/0x5c0 mm/memory.c:2104
exit_mmap+0x251/0xb30 mm/mmap.c:1277
__mmput+0xcb/0x3d0 kernel/fork.c:1174
exit_mm+0x168/0x220 kernel/exit.c:581
do_exit+0x62e/0x2320 kernel/exit.c:959
do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd87e48bf79
Code: Unable to access opcode bytes at 0x7fd87e48bf4f.
RSP: 002b:00007ffcace9eb58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fd87e53d308 RCX: 00007fd87e48bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007fd87e53d326 R08: 0000000000000000 R09: 00007ffcace9ec7c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007ffcace9ec7c R14: 00007ffcace9ed10 R15: 0000000000000000