INFO: task syz.6.211:8507 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.211 state:D stack:21064 pid:8507 tgid:8506 ppid:7845 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 __closure_sync+0x163/0x220 lib/closure.c:146 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:315 [inline] bch2_btree_update_start+0x18dc/0x1de0 fs/bcachefs/btree_update_interior.c:1293 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1921 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:914 __bch2_trans_commit+0x1bb5/0x8870 fs/bcachefs/btree_trans_commit.c:1104 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline] bch2_logged_op_start+0x177/0x290 fs/bcachefs/logged_ops.c:93 bch2_truncate+0x128/0x200 fs/bcachefs/io_misc.c:324 bchfs_truncate+0x8b1/0xc20 fs/bcachefs/fs-io.c:511 notify_change+0xb31/0xe60 fs/attr.c:552 do_truncate+0x1a4/0x220 fs/open.c:68 vfs_truncate+0x493/0x520 fs/open.c:118 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 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: 0033:0x7f2a2ac9eec9 RSP: 002b:00007f2a28f06038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f2a2aef5fa0 RCX: 00007f2a2ac9eec9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000200000000040 RBP: 00007f2a2ad21f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2a2aef6038 R14: 00007f2a2aef5fa0 R15: 00007ffe3f366c48 INFO: task bch-reclaim/loo:8515 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:bch-reclaim/loo state:D stack:23816 pid:8515 tgid:8515 ppid:2 task_flags:0x200840 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 __closure_sync+0x163/0x220 lib/closure.c:146 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:315 [inline] bch2_btree_update_start+0x18dc/0x1de0 fs/bcachefs/btree_update_interior.c:1293 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1921 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:914 __bch2_trans_commit+0x1bb5/0x8870 fs/bcachefs/btree_trans_commit.c:1104 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline] bch2_btree_write_buffer_flush_locked+0x451f/0x4dd0 fs/bcachefs/btree_write_buffer.c:454 btree_write_buffer_flush_seq+0x18c7/0x1a40 fs/bcachefs/btree_write_buffer.c:572 bch2_btree_write_buffer_journal_flush+0x69/0xb0 fs/bcachefs/btree_write_buffer.c:588 journal_flush_pins+0x8e3/0xe90 fs/bcachefs/journal_reclaim.c:604 __bch2_journal_reclaim+0x910/0xed0 fs/bcachefs/journal_reclaim.c:732 bch2_journal_reclaim_thread+0x177/0x4f0 fs/bcachefs/journal_reclaim.c:774 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8dc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8dc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8dc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/57: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000123fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000123fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:4/67: #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000152fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000152fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecc69a0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:172 [inline] #3: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:247 7 locks held by kworker/u8:10/3622: 2 locks held by dhcpcd/5502: #0: ffffffff8ecb7d78 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1321 #1: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:577 2 locks held by getty/5596: #0: ffff88823bf360a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:6/5993: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005d5fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005d5fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:0/8478: #0: ffff88814d679138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88814d679138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004687bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004687bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 5 locks held by syz.6.211/8507: #0: ffff888035f0a488 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888066fbd3f8 (&sb->s_type->i_mutex_key#36){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:875 [inline] #1: ffff888066fbd3f8 (&sb->s_type->i_mutex_key#36){++++}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63 #2: ffff888068e00a40 (&c->snapshot_create_lock){.+.+}-{4:4}, at: bch2_truncate+0xeb/0x200 fs/bcachefs/io_misc.c:322 #3: ffff888068e04678 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888068e04678 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888068e04678 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3299 #4: ffff888068e37360 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211 4 locks held by bch-reclaim/loo/8515: #0: ffff888068e6ce18 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:773 #1: ffff888068e04678 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffff888068e04678 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffff888068e04678 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f3/0xd80 fs/bcachefs/btree_iter.c:3505 #2: ffff888068e04a30 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x18bd/0x1a40 fs/bcachefs/btree_write_buffer.c:571 #3: ffff888068e37360 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211 1 lock held by syz-executor/9267: #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz-executor/9314: #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 1 lock held by syz-executor/9431: #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 7 locks held by syz-executor/9438: #0: ffff888033a6e488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline] #0: ffff888033a6e488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff888145737c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814473af08 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814473af08 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e542f38 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff888061cf40d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888061cf40d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffff888038d26300 (&devlink->lock_key#41){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1022 [inline] #6: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x800/0xf20 drivers/net/netdevsim/netdev.c:1105 2 locks held by syz-executor/9459: #0: ffffffff8f1efb10 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f1efb10 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f1efb10 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ecd38b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 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: 3622 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x2d/0xd20 kernel/locking/lockdep.c:5093 Code: 41 56 41 55 41 54 53 48 83 ec 30 48 89 fb 65 48 8b 3c 25 08 40 f6 91 45 31 ff 83 3d 1c 6f 81 0d 00 0f 84 7e 0c 00 00 48 8b 03 <48> 3d 00 f3 b9 92 0f 84 6f 0c 00 00 41 89 cc 41 89 d6 8b 0d 7b 8e RSP: 0018:ffffc9000d9c7750 EFLAGS: 00000002 RAX: ffffffff995e5de0 RBX: ffff888064ed01d8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888031195940 RBP: ffffffff8ac51734 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1e3ac47 R12: 0000000000000000 R13: ffff888064ed01d8 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559f65a98040 CR3: 000000000d7a6000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rt_spin_lock+0x88/0x2c0 kernel/locking/spinlock_rt.c:56 spin_lock_bh include/linux/spinlock_rt.h:88 [inline] batadv_nc_purge_paths+0x104/0x3f0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x87e/0xbc0 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245