INFO: task syz.0.621:9196 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.621 state:D stack:24056 pid:9196 tgid:9154 ppid:5864 task_flags:0x440140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:268 [inline] __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293 down+0x80/0xd0 kernel/locking/semaphore.c:100 xfs_buf_lock+0x15d/0x4d0 fs/xfs/xfs_buf.c:996 xfs_buf_find_lock+0x42/0x4c0 fs/xfs/xfs_buf.c:422 xfs_buf_lookup fs/xfs/xfs_buf.c:475 [inline] xfs_buf_get_map+0x10b7/0x1860 fs/xfs/xfs_buf.c:597 xfs_buf_read_map+0x82/0xa50 fs/xfs/xfs_buf.c:702 xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [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+0x60a/0x1300 fs/xfs/libxfs/xfs_alloc.c:2875 xfs_alloc_vextent_prepare_ag+0xdb/0x610 fs/xfs/libxfs/xfs_alloc.c:3566 xfs_alloc_vextent_iterate_ags+0x140/0x940 fs/xfs/libxfs/xfs_alloc.c:3750 xfs_alloc_vextent_start_ag+0x388/0x850 fs/xfs/libxfs/xfs_alloc.c:3839 xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3619 [inline] xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3664 [inline] xfs_bmapi_allocate+0x188e/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3939 xfs_bmapi_write+0x7df/0x1260 fs/xfs/libxfs/xfs_bmap.c:4268 xfs_iomap_write_direct+0x3b2/0x6b0 fs/xfs/xfs_iomap.c:326 xfs_direct_write_iomap_begin+0xfa3/0x13e0 fs/xfs/xfs_iomap.c:1000 iomap_iter+0x534/0xde0 fs/iomap/iter.c:108 __iomap_dio_rw+0xc57/0x1e30 fs/iomap/direct-io.c:727 iomap_dio_rw+0x45/0xb0 fs/iomap/direct-io.c:817 xfs_file_dio_write_aligned+0x157/0x1b0 fs/xfs/xfs_file.c:703 xfs_file_dio_write fs/xfs/xfs_file.c:914 [inline] xfs_file_write_iter+0x8b2/0xa60 fs/xfs/xfs_file.c:1126 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_pwritev fs/read_write.c:1153 [inline] __do_sys_pwritev2 fs/read_write.c:1211 [inline] __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f651598eba9 RSP: 002b:00007f6516821038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007f6515bd6090 RCX: 00007f651598eba9 RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000004 RBP: 00007f6515a11e19 R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000007800 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6515bd6128 R14: 00007f6515bd6090 R15: 00007ffd24b4a568 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:4/60: 2 locks held by getty/5634: #0: ffff88814cefa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036be2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u9:2/5871: #0: ffff8880521f9948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8880521f9948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000414fba0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000414fba0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88803035cdc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331 4 locks held by kworker/u8:9/6001: #0: ffff888141abf148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888141abf148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004e0fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004e0fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88806b0f00e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff888067037198 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_map_blocks fs/xfs/xfs_aops.c:370 [inline] #3: ffff888067037198 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_writeback_range+0x33d/0xf70 fs/xfs/xfs_aops.c:489 3 locks held by kworker/0:2H/6060: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644 #1: ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: xa_find_after+0xae/0x430 lib/xarray.c:2248 4 locks held by syz.0.621/9196: #0: ffff88806b0f0420 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3113 [inline] #0: ffff88806b0f0420 (sb_writers#17){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055 #1: ffff8880670373b0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: xfs_ilock_demote+0xbd/0x2b0 fs/xfs/xfs_inode.c:285 #2: ffff88806b0f0610 (sb_internal#4){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980 fs/xfs/xfs_trans.c:256 #3: ffff888067037198 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0 fs/xfs/xfs_trans.c:1081 4 locks held by syz.0.621/9207: #0: ffff88806b0f0420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:574 #1: ffff888067034e30 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff888067034e30 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff88806b0f0610 (sb_internal#4){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980 fs/xfs/xfs_trans.c:256 #3: ffff888067034c18 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0 fs/xfs/xfs_trans.c:1081 2 locks held by syz.4.679/9490: #0: ffff88806b0f00e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88806b0f00e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff888024e3c7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888024e3c7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2832 2 locks held by syz-executor/9682: #0: ffff8880732860e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880732860e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880732860e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffff888024f387d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888024f387d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2832 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 2b 25 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e007d80 EFLAGS: 000002c2 RAX: f1c9beb7d6002000 RBX: ffffffff81968208 RCX: f1c9beb7d6002000 RDX: 0000000000000001 RSI: ffffffff8dbbd648 RDI: ffffffff8c036f00 RBP: ffffffff8e007ea8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3 R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fc3f330 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c12a38 FS: 0000000000000000(0000) GS:ffff8881259e8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555609ce5c8 CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:756 start_kernel+0x3a9/0x410 init/main.c:1109 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147