INFO: task syz.2.648:8266 blocked for more than 143 seconds. Not tainted 6.15.0-rc7-next-20250523-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.648 state:D stack:26152 pid:8266 tgid:8265 ppid:5838 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: 0033:0x7fe01dd8e969 RSP: 002b:00007fe01eb90038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fe01dfb5fa0 RCX: 00007fe01dd8e969 RDX: 0000000000000002 RSI: 0000200000000000 RDI: 000000000000000a RBP: 00007fe01de10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe01dfb5fa0 R15: 00007ffc41755c68 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: 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/5595: #0: ffff8880347aa0a0 (&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 1 lock held by udevd/5835: 3 locks held by syz.2.648/8266: #0: ffff88802f46a478 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff88806b65a428 (sb_writers#18){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline] #1: ffff88806b65a428 (sb_writers#18){.+.+}-{0:0}, at: vfs_writev+0x274/0x9a0 fs/read_write.c:1055 #2: ffff88807d6a0148 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188 4 locks held by kworker/u8:13/8624: 1 lock held by syz.0.1182/10184: #0: ffff8880345780e0 (&type->s_umount_key#76/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-next-20250523-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: 10184 Comm: syz.0.1182 Not tainted 6.15.0-rc7-next-20250523-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:enqueue_entity+0x12/0x1120 kernel/sched/fair.c:5321 Code: 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 41 55 41 54 53 48 83 ec 38 89 54 24 08 <49> 89 f7 49 89 fd 49 bc 00 00 00 00 00 fc ff df 48 8d 5f 58 48 89 RSP: 0018:ffffc90000a08ae0 EFLAGS: 00000082 RAX: 1ffff11006152024 RBX: ffff888030a90000 RCX: dffffc0000000000 RDX: 0000000000000409 RSI: ffff888030a90080 RDI: ffff8880296ab000 RBP: 0000000000000409 R08: ffffffff8fa12ef7 R09: 1ffffffff1f425de R10: dffffc0000000000 R11: fffffbfff1f425df R12: 0000000000000000 R13: ffff888030a90080 R14: ffff8880296ab000 R15: ffff888030a90590 FS: 00007f62a45586c0(0000) GS:ffff888125d56000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c27350d CR3: 0000000027514000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: enqueue_task_fair+0x25a/0x1470 kernel/sched/fair.c:6985 enqueue_task+0x75/0x420 kernel/sched/core.c:2084 activate_task kernel/sched/core.c:2126 [inline] ttwu_do_activate+0x1ee/0x8b0 kernel/sched/core.c:3746 ttwu_queue kernel/sched/core.c:4014 [inline] try_to_wake_up+0x745/0x1290 kernel/sched/core.c:4342 hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:1997 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 c1 59 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 b0 59 1f 00 eb 06 e8 a9 59 1f 00 fb 48 c7 c7 e0 32 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 36 RSP: 0018:ffffc9001e126520 EFLAGS: 00000287 RAX: ffffffff81a0e987 RBX: ffffffff81a0e844 RCX: 0000000000080000 RDX: ffffc9000c5da000 RSI: 0000000000007626 RDI: ffffffff8e1332e0 RBP: ffffc9001e126630 R08: ffffffff8fa12ef7 R09: 1ffffffff1f425de R10: dffffc0000000000 R11: fffffbfff1f425df R12: dffffc0000000000 R13: 1ffff92003c24ca8 R14: 0000000000000200 R15: 000000000000005f _printk+0xcf/0x120 kernel/printk/printk.c:2475 __xfs_printk fs/xfs/xfs_message.c:24 [inline] _xfs_alert_tag+0x1cb/0x2d0 fs/xfs/xfs_message.c:74 xfs_buf_verifier_error+0x150/0x2a0 fs/xfs/xfs_error.c:455 xfs_agf_read_verify+0x16e/0x1f0 fs/xfs/libxfs/xfs_alloc.c:-1 __xfs_buf_ioend+0x342/0x6f0 fs/xfs/xfs_buf.c:1177 xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1384 _xfs_buf_read fs/xfs/xfs_buf.c:646 [inline] xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:712 xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline] xfs_read_agf+0x281/0x5c0 fs/xfs/libxfs/xfs_alloc.c:3376 xfs_alloc_read_agf+0x17c/0xb70 fs/xfs/libxfs/xfs_alloc.c:3411 xfs_alloc_fix_freelist+0x1a3/0x1300 fs/xfs/libxfs/xfs_alloc.c:2844 xfs_free_extent_fix_freelist fs/xfs/libxfs/xfs_alloc.c:3965 [inline] __xfs_free_extent+0x17a/0x470 fs/xfs/libxfs/xfs_alloc.c:4001 xfs_extent_free_finish_item+0x28b/0x670 fs/xfs/xfs_extfree_item.c:552 xfs_defer_finish_one+0x5c8/0xcf0 fs/xfs/libxfs/xfs_defer.c:595 xfs_defer_finish_noroll+0x910/0x12d0 fs/xfs/libxfs/xfs_defer.c:707 xfs_defer_finish+0x1c/0x180 fs/xfs/libxfs/xfs_defer.c:741 xfs_bunmapi_range+0xc4/0x140 fs/xfs/libxfs/xfs_bmap.c:6178 xfs_itruncate_extents_flags+0x306/0x990 fs/xfs/xfs_inode.c:1066 xfs_itruncate_extents fs/xfs/xfs_inode.h:593 [inline] xfs_setattr_size+0x9eb/0xf10 fs/xfs/xfs_iops.c:1096 xfs_vn_setattr+0x258/0x300 fs/xfs/xfs_iops.c:1172 notify_change+0xb36/0xe40 fs/attr.c:552 do_truncate+0x1a4/0x220 fs/open.c:68 handle_truncate fs/namei.c:3508 [inline] do_open fs/namei.c:3891 [inline] path_openat+0x306c/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: 0033:0x7f62a378e969 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:00007f62a4558038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f62a39b5fa0 RCX: 00007f62a378e969 RDX: 0000000000183741 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f62a3810ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000042 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f62a39b5fa0 R15: 00007fffd7d89fa8