INFO: task kworker/u8:7:3499 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:7 state:D stack:21112 pid:3499 tgid:3499 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-15) Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2171 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.6.76:6708 blocked for more than 144 seconds. Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.76 state:D stack:19816 pid:6708 tgid:6707 ppid:6131 task_flags:0x400140 flags:0x00024006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 __closure_sync+0x163/0x220 lib/closure.c:146 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:256 [inline] bch2_btree_update_start+0x1193/0x14c0 fs/bcachefs/btree_update_interior.c:1251 bch2_btree_split_leaf+0x13c/0x8f0 fs/bcachefs/btree_update_interior.c:1864 bch2_trans_commit_error+0x1a8/0x1100 fs/bcachefs/btree_trans_commit.c:904 __bch2_trans_commit+0x779c/0x8ae0 fs/bcachefs/btree_trans_commit.c:1069 bch2_trans_commit fs/bcachefs/btree_update.h:195 [inline] bch2_rename2+0xda1/0x1340 fs/bcachefs/fs.c:1009 vfs_rename+0xb99/0xec0 fs/namei.c:5121 do_renameat2+0x878/0xc50 fs/namei.c:5270 __do_sys_renameat2 fs/namei.c:5304 [inline] __se_sys_renameat2 fs/namei.c:5301 [inline] __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5301 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffbaeb8e969 RSP: 002b:00007ffbafa4a038 EFLAGS: 00000246 ORIG_RAX: 000000000000013c RAX: ffffffffffffffda RBX: 00007ffbaedb5fa0 RCX: 00007ffbaeb8e969 RDX: ffffffffffffff9c RSI: 0000200000000180 RDI: ffffffffffffff9c RBP: 00007ffbaec10ab1 R08: 0000000000000004 R09: 0000000000000000 R10: 0000200000001240 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffbaedb5fa0 R15: 00007ffe38aa6cf8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:2/36: #0: ffff88801db79948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801db79948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000ad7c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ad7c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 4 locks held by kworker/u8:7/3499: #0: ffff88801feb1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801feb1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000b5cfc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b5cfc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff888031ad60e0 (&type->s_umount_key#64){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88807ca932c0 (&inode->ei_update_lock){+.+.}-{4:4}, at: bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2171 1 lock held by dhcpcd/5482: #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121 2 locks held by getty/5570: #0: ffff88803507a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5819: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 12 locks held by syz.6.76/6708: #0: ffff888031ad6420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff888031ad6730 (&type->s_vfs_rename_key#3){+.+.}-{4:4}, at: lock_rename fs/namei.c:3269 [inline] #1: ffff888031ad6730 (&type->s_vfs_rename_key#3){+.+.}-{4:4}, at: do_renameat2+0x37f/0xc50 fs/namei.c:5216 #2: ffff88807ca91fa8 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #2: ffff88807ca91fa8 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: lock_two_directories+0x1a2/0x220 fs/namei.c:3245 #3: ffff88807ca92740 (&sb->s_type->i_mutex_key#22/5){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #3: ffff88807ca92740 (&sb->s_type->i_mutex_key#22/5){+.+.}-{4:4}, at: lock_two_directories+0x1cc/0x220 fs/namei.c:3246 #4: ffff88805c0f1810 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #4: ffff88805c0f1810 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: lock_two_nondirectories+0xe7/0x180 fs/inode.c:1233 #5: ffff88807ca92ed8 (&sb->s_type->i_mutex_key#22/4){+.+.}-{4:4}, at: vfs_rename+0x69a/0xec0 fs/namei.c:5092 #6: ffff88805c0f1bf8 (&inode->ei_update_lock/1){+.+.}-{4:4}, at: bch2_rename2+0x363/0x1340 fs/bcachefs/fs.c:943 #7: ffff88807ca92390 (&inode->ei_update_lock/2){+.+.}-{4:4}, at: bch2_rename2+0x37e/0x1340 fs/bcachefs/fs.c:943 #8: ffff88807ca92b28 (&inode->ei_update_lock/3){+.+.}-{4:4}, at: bch2_rename2+0x3be/0x1340 fs/bcachefs/fs.c:943 #9: ffff88807ca932c0 (&inode->ei_update_lock/4){+.+.}-{4:4}, at: bch2_rename2+0x3ed/0x1340 fs/bcachefs/fs.c:943 #10: ffff888054804228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #10: ffff888054804228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #10: ffff888054804228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202 #11: ffff888054826590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 1 lock held by bch-copygc/loop/6768: 3 locks held by kworker/u8:8/6823: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90003f47c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003f47c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 8 locks held by syz-executor/9482: #0: ffff888031a4c420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888031a4c420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff88802a373888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff888026d34b48 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8eb820e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216 #4: ffff88805ef8c0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff88805ef8c0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff88805ef8c0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 #5: ffff88805ef8d250 (&devlink->lock_key#2){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xdb/0x670 drivers/net/netdevsim/netdev.c:1059 #7: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #7: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 6819 Comm: syz-executor Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:deref_stack_reg+0x19f/0x230 arch/x86/kernel/unwind_orc.c:406 Code: 20 c2 20 ca 80 fa 01 75 46 49 8d 40 08 48 39 d8 0f 97 c1 4c 39 f0 0f 96 c0 20 c8 3c 01 75 30 4c 89 c7 49 89 f7 e8 11 08 00 00 <49> 89 c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 RSP: 0018:ffffc90000007380 EFLAGS: 00000202 RAX: 0000000000000820 RBX: ffffc90000000000 RCX: 0000000000000001 RDX: ffffc900000074e8 RSI: dffffc0000000000 RDI: ffffc90000007808 RBP: 1ffff92000000e95 R08: ffffc90000007808 R09: 0000000000000000 R10: ffffc900000074f8 R11: fffff52000000ea1 R12: 1ffff92000000e96 R13: 1ffff92000000e97 R14: ffffc90000008000 R15: dffffc0000000000 FS: 0000555592ec9500(0000) GS:ffff888126100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b527b5ff38 CR3: 0000000052194000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4262 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:658 skb_copy+0x188/0x800 net/core/skbuff.c:2131 mac80211_hwsim_tx_frame_no_nl+0xc85/0x1180 drivers/net/wireless/virtual/mac80211_hwsim.c:1866 mac80211_hwsim_tx_frame+0x1b5/0x200 drivers/net/wireless/virtual/mac80211_hwsim.c:2217 mac80211_hwsim_beacon_tx+0x3f6/0x860 drivers/net/wireless/virtual/mac80211_hwsim.c:2317 __iterate_interfaces+0x2a8/0x590 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797 mac80211_hwsim_beacon+0xbb/0x1c0 drivers/net/wireless/virtual/mac80211_hwsim.c:2347 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 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 31 f3 1e 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 20 f3 1e 00 eb 06 e8 19 f3 1e 00 fb 48 c7 c7 80 fa f2 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 f9 3f RSP: 0018:ffffc9000311f980 EFLAGS: 00000293 RAX: ffffffff81a0cc47 RBX: ffffffff81a0cb04 RCX: ffff88802d6e0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df2fa80 RBP: ffffc9000311fa90 R08: ffffffff8f7da977 R09: 1ffffffff1efb52e R10: dffffc0000000000 R11: fffffbfff1efb52f R12: dffffc0000000000 R13: 1ffff92000623f34 R14: 0000000000000200 R15: 0000000000000047 _printk+0xcf/0x120 kernel/printk/printk.c:2475 __xfs_printk fs/xfs/xfs_message.c:24 [inline] xfs_printk_level+0x18b/0x280 fs/xfs/xfs_message.c:44 xfs_fs_put_super+0x55/0x160 fs/xfs/xfs_super.c:1232 generic_shutdown_super+0x132/0x2c0 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1710 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2220 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f622858fc97 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd36cdb3d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f622861089d RCX: 00007f622858fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd36cdb490 RBP: 00007ffd36cdb490 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd36cdc520 R13: 00007f622861089d R14: 0000000000050900 R15: 00007ffd36cdc560