INFO: task kworker/u8:1:12 blocked for more than 143 seconds. Not tainted 6.12.0-syzkaller-12128-gf788b5ef1ca9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:23760 pid:12 tgid:12 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-5) Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 io_schedule+0x8d/0x110 kernel/sched/core.c:7681 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1308 writeback_get_folio mm/page-writeback.c:2515 [inline] writeback_iter+0x8e0/0x1730 mm/page-writeback.c:2609 write_cache_pages+0xb1/0x230 mm/page-writeback.c:2658 bch2_writepages+0x156/0x390 fs/bcachefs/fs-io-buffered.c:639 do_writepages+0x35f/0x880 mm/page-writeback.c:2702 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0xc4b/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task syz.2.33:6067 blocked for more than 144 seconds. Not tainted 6.12.0-syzkaller-12128-gf788b5ef1ca9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.33 state:D stack:18040 pid:6067 tgid:6066 ppid:5822 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 io_schedule+0x8d/0x110 kernel/sched/core.c:7681 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1308 folio_wait_writeback+0xe7/0x1e0 mm/page-writeback.c:3194 folio_prepare_writeback mm/page-writeback.c:2474 [inline] writeback_get_folio mm/page-writeback.c:2516 [inline] writeback_iter+0xa6a/0x1730 mm/page-writeback.c:2609 write_cache_pages+0xb1/0x230 mm/page-writeback.c:2658 bch2_writepages+0x156/0x390 fs/bcachefs/fs-io-buffered.c:639 do_writepages+0x35f/0x880 mm/page-writeback.c:2702 filemap_fdatawrite_wbc mm/filemap.c:397 [inline] __filemap_fdatawrite_range mm/filemap.c:430 [inline] file_write_and_wait_range+0x2a3/0x3c0 mm/filemap.c:787 bch2_fsync+0x13a/0x350 fs/bcachefs/fs-io.c:199 generic_write_sync include/linux/fs.h:2904 [inline] bch2_write_iter+0x222f/0x2440 fs/bcachefs/fs-io-buffered.c:1061 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_pwrite64 fs/read_write.c:786 [inline] __do_sys_pwrite64 fs/read_write.c:794 [inline] __se_sys_pwrite64 fs/read_write.c:791 [inline] __x64_sys_pwrite64+0x1ac/0x240 fs/read_write.c:791 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2378380849 RSP: 002b:00007f2379198058 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f2378545fa0 RCX: 00007f2378380849 RDX: 000000000000fdef RSI: 0000000020000140 RDI: 0000000000000006 RBP: 00007f23783f3986 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fecc R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2378545fa0 R15: 00007ffdcf1ccdd8 Showing all locks held in the system: 3 locks held by kworker/0:0/8: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc900000d7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900000d7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88805e154538 (&idev->mc_lock){+.+.}-{4:4}, at: mld_dad_work+0x3c/0x500 net/ipv6/mcast.c:2259 3 locks held by kworker/u8:1/12: #0: ffff888142683148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888142683148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff888033fd40e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 1 lock held by khungtaskd/30: #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 5 locks held by kworker/u8:3/52: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000bc7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bc7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc90c50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586 #3: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1664 #4: ffff888030340768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: wiphy_lock include/net/cfg80211.h:6019 [inline] #4: ffff888030340768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_netdev_notifier_call+0x1a8/0x1480 net/wireless/core.c:1546 3 locks held by kworker/0:2/877: 2 locks held by dhcpcd/5487: #0: ffff88803410e6c8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xcb/0xe10 net/netlink/af_netlink.c:2263 #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6785 2 locks held by getty/5585: #0: ffff888035e410a0 (&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+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz.2.33/6067: #0: ffff888033fd4420 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #0: ffff888033fd4420 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675 1 lock held by syz.2.33/6102: #0: ffff888033fd4420 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #0: ffff888033fd4420 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675 1 lock held by syz-executor/8139: #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz-executor/8358: #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.7.306/8440: #0: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 2 locks held by syz-executor/8517: #0: ffffffff8fc90c50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:496 #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x84/0x290 net/ipv4/nexthop.c:3878 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller-12128-gf788b5ef1ca9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8139 Comm: syz-executor Not tainted 6.12.0-syzkaller-12128-gf788b5ef1ca9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:unwind_get_return_address+0x56/0x90 arch/x86/kernel/unwind_orc.c:369 Code: 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 5b 86 bb 00 48 8b 3b e8 73 73 1e 00 85 c0 74 14 43 80 3c 37 00 <74> 08 48 89 df e8 40 86 bb 00 48 8b 03 eb 02 31 c0 5b 41 5e 41 5f RSP: 0018:ffffc90003047500 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc90003047568 RCX: ffffffff91772000 RDX: ffffffff91920f01 RSI: ffffc90003040000 RDI: ffffffff8bc76c80 RBP: ffffc900030475b0 R08: ffffc90003047f00 R09: 0000000000000000 R10: ffffc90003047570 R11: fffff52000608eb0 R12: ffff888026bebc00 R13: ffffffff818b36a0 R14: dffffc0000000000 R15: 1ffff92000608ead FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055cf3bc37958 CR3: 000000003394c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xde3/0x1130 mm/page_alloc.c:2657 vfree+0x186/0x2e0 mm/vmalloc.c:3382 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6567d826dc Code: Unable to access opcode bytes at 0x7f6567d826b2. RSP: 002b:00007fff1256fdf0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 0000000000000028 RBX: 00007f6568a74620 RCX: 00007f6567d826dc RDX: 0000000000000028 RSI: 00007f6568a74670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff1256fe44 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f6568a74670 R15: 0000000000000000