INFO: task kworker/u4:12:2974 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:12 state:D stack:22072 pid:2974 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
INFO: task syz.0.479:8189 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.479 state:D stack:27944 pid:8189 ppid:5762 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
__lock_metapage fs/jfs/jfs_metapage.c:50 [inline]
lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64
__get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639
ea_write+0x5e3/0xdd0 fs/jfs/xattr.c:256
ea_put fs/jfs/xattr.c:626 [inline]
__jfs_setxattr+0x931/0x1150 fs/jfs/xattr.c:792
__jfs_set_acl+0x121/0x1b0 fs/jfs/acl.c:87
jfs_set_acl+0x1d7/0x320 fs/jfs/acl.c:115
posix_acl_chmod+0x1d1/0x270 fs/posix_acl.c:628
notify_change+0xb0d/0xe10 fs/attr.c:499
chmod_common+0x250/0x3f0 fs/open.c:643
do_fchmodat+0x134/0x200 fs/open.c:691
__do_sys_fchmodat fs/open.c:710 [inline]
__se_sys_fchmodat fs/open.c:707 [inline]
__x64_sys_fchmodat+0x7d/0x90 fs/open.c:707
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8e7638f749
RSP: 002b:00007f8e77218038 EFLAGS: 00000246 ORIG_RAX: 000000000000010c
RAX: ffffffffffffffda RBX: 00007f8e765e6090 RCX: 00007f8e7638f749
RDX: 00000000fffffffb RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f8e76413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8e765e6128 R14: 00007f8e765e6090 R15: 00007ffd95110fa8
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:4/59:
2 locks held by kworker/u4:8/1140:
4 locks held by kworker/u4:12/2974:
#0: ffff88801a246938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a246938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000c7b7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000c7b7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88807a5740e0 (&type->s_umount_key#115){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88804f0ab008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
2 locks held by getty/5531:
#0: ffff88802cd840a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900015d02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
4 locks held by syz.0.479/8189:
#0: ffff88807a574418 (sb_writers#40){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff88804f0ab3d0 (&type->i_mutex_dir_key#25){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff88804f0ab3d0 (&type->i_mutex_dir_key#25){++++}-{3:3}, at: chmod_common+0x188/0x3f0 fs/open.c:637
#2: ffff88804f0ab008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_set_acl+0x10a/0x320 fs/jfs/acl.c:107
#3: ffff88804f0ab0a0 (&jfs_ip->xattr_sem){+.+.}-{3:3}, at: __jfs_setxattr+0xe2/0x1150 fs/jfs/xattr.c:678
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 59 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:check_wait_context kernel/locking/lockdep.c:-1 [inline]
RIP: 0010:__lock_acquire+0x5dc/0x7c80 kernel/locking/lockdep.c:5087
Code: b0 82 15 00 0f 84 f6 01 00 00 31 db 48 81 c3 c8 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 1b 63 00 00 44 0f b6 33 <48> 8b 44 24 48 0f b6 04 10 84 c0 0f 85 2a 63 00 00 41 8b 07 89 c3
RSP: 0018:ffffc900015a74e0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff906feab8 RCX: ffffffff816703b0
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff90d94500
RBP: ffffc900015a7728 R08: ffffffff90d94507 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: ffff88801e6d28c4
R13: ffff88801e6d1e00 R14: 0000000000000002 R15: ffff88801e6d29a0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1bffb6ad8 CR3: 0000000079e89000 CR4: 00000000003506f0
Call Trace:
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
crng_make_state+0x158/0x700 drivers/char/random.c:347
_get_random_bytes+0xd6/0x210 drivers/char/random.c:385
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:775 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x646/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293