INFO: task kworker/u4:14:4621 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:14 state:D stack:22560 pid:4621 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
hfsplus_ext_write_extent+0x8d/0x230 fs/hfsplus/extents.c:149
hfsplus_write_inode+0x1e/0x570 fs/hfsplus/super.c:171
write_inode fs/fs-writeback.c:1536 [inline]
__writeback_single_inode+0x76c/0x1170 fs/fs-writeback.c:1753
writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1979
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2050
wb_writeback+0x484/0xd40 fs/fs-writeback.c:2155
wb_check_background_flush fs/fs-writeback.c:2221 [inline]
wb_do_writeback fs/fs-writeback.c:2309 [inline]
wb_workfn+0xc1c/0xee0 fs/fs-writeback.c:2336
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 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.1.154:5027 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.154 state:D stack:23528 pid:5027 ppid:4272 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
hfsplus_file_truncate+0x39b/0xb60 fs/hfsplus/extents.c:580
hfsplus_write_begin+0xc8/0xd0 fs/hfsplus/inode.c:56
generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862
__generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960
generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989
call_write_iter include/linux/fs.h:2271 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd20e79e559
RSP: 002b:00007fd20f63e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fd20ea25fa0 RCX: 00007fd20e79e559
RDX: 000000000000fea7 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007fd20e8358b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd20ea26038 R14: 00007fd20ea25fa0 R15: 00007fffe9e29e08
INFO: task syz.1.154:5034 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.154 state:D stack:20832 pid:5034 ppid:4272 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
hfsplus_bnode_find+0x341/0xd00 fs/hfsplus/bnode.c:539
hfs_bnode_split+0x297/0xed0 fs/hfsplus/brec.c:258
hfsplus_brec_insert+0x394/0xcc0 fs/hfsplus/brec.c:100
__hfsplus_ext_write_extent+0x318/0x520 fs/hfsplus/extents.c:107
__hfsplus_ext_cache_extent+0x81/0xbd0 fs/hfsplus/extents.c:186
hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
hfsplus_file_extend+0x4b9/0x1a40 fs/hfsplus/extents.c:459
hfsplus_get_block+0x41d/0x1520 fs/hfsplus/extents.c:245
__block_write_begin_int+0x577/0x1ab0 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x96/0x1e0 fs/buffer.c:2102
cont_write_begin+0x5f9/0x800 fs/buffer.c:2456
hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52
generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862
__generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960
generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989
__kernel_write_iter+0x298/0x690 fs/read_write.c:517
dump_emit_page fs/coredump.c:950 [inline]
dump_user_range+0x40a/0x840 fs/coredump.c:977
elf_core_dump+0x30ca/0x3630 fs/binfmt_elf.c:2354
do_coredump+0x16c1/0x2480 fs/coredump.c:824
get_signal+0x1093/0x1340 kernel/signal.c:2870
arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:319
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1485
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fd20e79e561
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fd20ea26180 RCX: 00007fd20e79e559
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fd20e8358b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd20ea26218 R14: 00007fd20ea26180 R15: 00007fffe9e29e08
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d92e230 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d92ea50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
2 locks held by getty/4027:
#0: ffff88814d2d4098 (&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+0x41e/0x1360 drivers/tty/n_tty.c:2198
4 locks held by kworker/u4:14/4621:
#0: ffff888144a54938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90004cc7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff8880572160e0 (&type->s_umount_key#54){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
#3: ffff888055200e08 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_ext_write_extent+0x8d/0x230 fs/hfsplus/extents.c:149
5 locks held by syz.1.154/5027:
#0: ffff88807bebafe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888057216460 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff888055200fb0 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
#2: ffff888055200fb0 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986
#3: ffff888055200e08 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2b3/0xb60 fs/hfsplus/extents.c:574
#4: ffff888074a100b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
4 locks held by syz.1.154/5034:
#0: ffff888057216460 (sb_writers#14){.+.+}-{0:0}, at: do_coredump+0x169d/0x2480 fs/coredump.c:823
#1: ffff8880553350b0 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
#1: ffff8880553350b0 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986
#2: ffff888055334f08 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1ca/0x1a40 fs/hfsplus/extents.c:455
#3: ffff888074a100b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0xf0e/0xf50 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4630 Comm: kworker/u4:17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:chacha_permute+0x414/0xef0 lib/crypto/chacha.c:52
Code: c1 41 31 ce 41 c1 c6 0c 44 8b 0c 24 41 01 e9 44 89 0c 24 45 31 cf 41 c1 c7 0c 45 89 e1 44 8b 64 24 0c 41 01 dc 44 89 64 24 0c <45> 31 e3 45 89 cc 41 c1 c3 0c 45 01 ca 44 89 54 24 08 45 31 d5 41
RSP: 0018:ffffc90004b0f610 EFLAGS: 00000092
RAX: 000000003d905644 RBX: 0000000050b6bd54 RCX: 000000005a915385
RDX: 00000000cc92e2f2 RSI: 0000000021dc9eee RDI: 00000000a284dc46
RBP: 00000000f1717d43 R08: 000000008d420191 R09: 00000000cb544221
R10: 00000000278cbdc4 R11: 00000000e93ce924 R12: 00000000f711c3a1
R13: 00000000199e0c2e R14: 00000000c7e415ca R15: 000000009b777003
FS: 0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f73733f22f8 CR3: 000000007dc97000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
chacha_block_generic+0xb3/0xd80 lib/crypto/chacha.c:83
chacha20_block include/crypto/chacha.h:36 [inline]
crng_fast_key_erasure drivers/char/random.c:259 [inline]
crng_make_state+0x3b2/0xb00 drivers/char/random.c:352
_get_random_bytes+0xfc/0x250 drivers/char/random.c:366
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+0x5fa/0xa80 drivers/net/netdevsim/dev.c:851
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295