INFO: task kworker/u8:5:5924 blocked for more than 143 seconds. Not tainted 6.13.0-rc3-syzkaller-00017-gf44d154d6e3d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:5 state:D stack:18832 pid:5924 tgid:5924 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-23) 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+0x839/0xee0 mm/filemap.c:1308 folio_lock include/linux/pagemap.h:1151 [inline] writeback_get_folio mm/page-writeback.c:2515 [inline] writeback_iter+0x8ad/0x12b0 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.2.124:7109 blocked for more than 144 seconds. Not tainted 6.13.0-rc3-syzkaller-00017-gf44d154d6e3d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.124 state:D stack:22872 pid:7109 tgid:7052 ppid:5857 flags:0x00004006 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+0x839/0xee0 mm/filemap.c:1308 folio_wait_writeback+0xb0/0x100 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+0xa13/0x12b0 mm/page-writeback.c:2609 write_cache_pages+0x14d/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+0x2918/0x2c10 fs/bcachefs/fs-io-buffered.c:1061 iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11b/0x220 fs/splice.c:1164 splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x289/0x3e0 fs/splice.c:1233 do_sendfile+0x564/0x8a0 fs/read_write.c:1363 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410 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: 0033:0x7f5004b85d19 RSP: 002b:00007f5005a7d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5004d76080 RCX: 00007f5004b85d19 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 00007f5004c01a20 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007a680000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f5004d76080 R15: 00007ffdf0611eb8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 2 locks held by kworker/u8:2/35: 2 locks held by kworker/u8:11/3568: #0: ffff8880b863e758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #1: ffff8880b8628948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 1 lock held by dhcpcd/5491: #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbcb/0x2150 net/core/rtnetlink.c:4010 2 locks held by getty/5582: #0: ffff88814d2850a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032fb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5855: #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 3 locks held by kworker/u8:1/5898: 3 locks held by kworker/u8:4/5902: #0: ffff88803179f948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88803179f948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000433fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000433fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4215 3 locks held by kworker/u8:5/5924: #0: ffff88801e6b9948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801e6b9948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc900043dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900043dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88805f2ba0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 1 lock held by syz.2.124/7053: #0: ffff88805f2ba420 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #0: ffff88805f2ba420 (sb_writers#17){.+.+}-{0:0}, at: vfs_writev+0x2d1/0xba0 fs/read_write.c:1048 1 lock held by syz.2.124/7109: #0: ffff88805f2ba420 (sb_writers#17){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x220 fs/splice.c:1163 2 locks held by syz.6.246/7986: #0: ffff88805f2ba0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805f2ba0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88807bdfe7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88807bdfe7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 3 locks held by syz-executor/9601: #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fca0508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbcb/0x2150 net/core/rtnetlink.c:4010 #1: ffff88805d41d4e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x22d/0x420 drivers/net/wireguard/device.c:50 #2: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc3-syzkaller-00017-gf44d154d6e3d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5879 Comm: kworker/u8:0 Not tainted 6.13.0-rc3-syzkaller-00017-gf44d154d6e3d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_acquire+0x2f/0x550 kernel/locking/lockdep.c:5817 Code: 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 20 01 00 00 4c 89 4c 24 28 4c 89 44 24 38 48 89 4c 24 30 89 54 24 1c <41> 89 f6 48 89 7c 24 20 65 48 8b 04 25 28 00 00 00 48 89 84 24 00 RSP: 0018:ffffc900041df9e0 EFLAGS: 00000282 RAX: ffffffff8b8bc95b RBX: ffff88805d78a540 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e937ae0 RBP: ffffc900041dfb40 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff20309e7 R12: ffff88807bca0d80 R13: 000000000000035d R14: ffff88805d78a540 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f98380a56e6 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 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