INFO: task syz.0.2427:16086 blocked for more than 143 seconds.
Not tainted 6.15.0-rc7-next-20250522-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2427 state:D stack:25880 pid:16086 tgid:16084 ppid:5840 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
netfs_wait_for_request+0x1f0/0x600 fs/netfs/misc.c:450
netfs_unbuffered_write_iter_locked+0x52a/0x910 fs/netfs/direct_write.c:110
netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:193
do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1
vfs_writev+0x306/0x9a0 fs/read_write.c:1057
do_writev+0x14d/0x2d0 fs/read_write.c:1103
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1aeb78e969
RSP: 002b:00007f1aec670038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f1aeb9b5fa0 RCX: 00007f1aeb78e969
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f1aeb810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1aeb9b5fa0 R15: 00007ffd99069338
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5597:
#0: ffff88803098b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/u8:11/6243:
1 lock held by syz-executor/7822:
#0: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#0: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
3 locks held by syz.0.2427/16086:
#0: ffff888029e7f978 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
#1: ffff8880292f4428 (sb_writers#24){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline]
#1: ffff8880292f4428 (sb_writers#24){.+.+}-{0:0}, at: vfs_writev+0x274/0x9a0 fs/read_write.c:1055
#2: ffff888056101498 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188
2 locks held by syz.9.2814/17635:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 17631 Comm: syz.8.2813 Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline]
RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline]
RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:233 [inline]
RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/x2apic_phys.c:113 [inline]
RIP: 0010:x2apic_send_IPI+0x73/0xe0 arch/x86/kernel/apic/x2apic_phys.c:50
Code: 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 42 41 8b 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f 5d e9 0e ba f5 09 cc 89 fe 89 fd 48 c7
RSP: 0018:ffffc9000362f8f0 EFLAGS: 00000206
RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830
RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000
RBP: ffffc9000362f9f8 R08: ffffffff8fa124f7 R09: 1ffffffff1f4249e
R10: dffffc0000000000 R11: ffffffff81702060 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880b86201b0 R15: ffffffff8dba2c60
FS: 00007f41972796c0(0000) GS:ffff888125d59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6cdbb80178 CR3: 0000000028c62000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
generic_exec_single+0x20e/0x500 kernel/smp.c:444
smp_call_function_single_async+0x79/0x110 kernel/smp.c:724
rdmsr_safe_on_cpu+0x127/0x230 arch/x86/lib/msr-smp.c:179
msr_read+0x14d/0x250 arch/x86/kernel/msr.c:66
vfs_read+0x200/0x980 fs/read_write.c:570
ksys_read+0x145/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f419638e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4197279038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f41965b5fa0 RCX: 00007f419638e969
RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 0000000000000004
RBP: 00007f4196410ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f41965b5fa0 R15: 00007ffcaa4cd308