INFO: task kworker/u8:2:36 blocked for more than 143 seconds. Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:2 state:D stack:23304 pid:36 tgid:36 ppid:2 task_flags:0x4248160 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit_lock+0x112/0x1a0 kernel/sched/wait_bit.c:90 out_of_line_wait_on_bit_lock+0xd9/0x110 kernel/sched/wait_bit.c:117 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer+0x67/0x70 fs/buffer.c:71 lock_buffer include/linux/buffer_head.h:434 [inline] do_get_write_access+0x8cd/0x12a0 fs/jbd2/transaction.c:968 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_mb_mark_context+0x175/0xd40 fs/ext4/mballoc.c:4001 ext4_mb_mark_diskspace_used+0x466/0x8c0 fs/ext4/mballoc.c:4131 ext4_mb_new_blocks+0xa5b/0x4f00 fs/ext4/mballoc.c:6233 ext4_ext_map_blocks+0x1b95/0x5d60 fs/ext4/extents.c:4379 ext4_map_create_blocks fs/ext4/inode.c:520 [inline] ext4_map_blocks+0x45b/0x1390 fs/ext4/inode.c:706 mpage_map_one_extent fs/ext4/inode.c:2224 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2277 [inline] ext4_do_writepages+0x1a2c/0x3490 fs/ext4/inode.c:2739 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2829 do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2047 wb_writeback+0x7f3/0xb70 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+0x8ca/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task jbd2/sda1-8:5164 blocked for more than 143 seconds. Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25224 pid:5164 tgid:5164 ppid:2 task_flags:0x240040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 jbd2_journal_wait_updates+0x11e/0x240 fs/jbd2/transaction.c:843 jbd2_journal_commit_transaction+0x828/0x6830 fs/jbd2/commit.c:454 kjournald2+0x1f4/0x760 fs/jbd2/journal.c:201 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task dhcpcd:5496 blocked for more than 144 seconds. Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:23064 pid:5496 tgid:5496 ppid:5495 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] __wait_on_buffer+0x64/0x70 fs/buffer.c:123 wait_on_buffer include/linux/buffer_head.h:422 [inline] __ext4_find_entry+0x97b/0x11c0 fs/ext4/namei.c:1613 ext4_lookup_entry fs/ext4/namei.c:1705 [inline] ext4_lookup+0x53d/0x730 fs/ext4/namei.c:1773 lookup_open.isra.0+0x4d7/0x1580 fs/namei.c:3679 open_last_lookups fs/namei.c:3800 [inline] path_openat+0x905/0x2d40 fs/namei.c:4036 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f647294f9a4 RSP: 002b:00007ffc187662e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000000100a0 RCX: 00007f647294f9a4 RDX: 0000000000000000 RSI: 00007ffc18776578 RDI: 00000000ffffff9c RBP: 00007ffc18776578 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc187663f8 R14: 00007ffc187663f8 R15: 0000000000000000 INFO: task syz-executor:5819 blocked for more than 144 seconds. Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:23240 pid:5819 tgid:5819 ppid:5817 task_flags:0x400100 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0x524/0x1310 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d6/0x200 kernel/locking/rwsem.c:1578 ext4_da_map_blocks fs/ext4/inode.c:1814 [inline] ext4_da_get_block_prep+0x69e/0x11e0 fs/ext4/inode.c:1878 __block_write_begin_int+0x4f1/0x16d0 fs/buffer.c:2151 block_page_mkwrite+0x3d3/0x4b0 fs/buffer.c:2646 ext4_page_mkwrite+0x8d8/0x1750 fs/ext4/inode.c:6242 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fa0a8e77dcf RSP: 002b:00007ffef9738be0 EFLAGS: 00010202 RAX: 00007fa0a7368000 RBX: 000000000000015a RCX: 0000000000000001 RDX: 1ffffffff140bfe1 RSI: 00005555649503a8 RDI: 0000000000000002 RBP: 00007ffef9738ed0 R08: 00005555649503b0 R09: 00000000000017fc R10: 00007fa0a8e00000 R11: 00007ffef97390e0 R12: 00007ffef9738f30 R13: 0000000000000004 R14: 00007ffef9738c50 R15: 00007ffef9738d20 INFO: task syz.4.776:10746 blocked for more than 144 seconds. Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.776 state:D stack:27432 pid:10746 tgid:10706 ppid:8809 task_flags:0x440040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 folio_wait_bit_common+0x3d6/0x9e0 mm/filemap.c:1317 folio_lock include/linux/pagemap.h:1137 [inline] mpage_prepare_extent_to_map+0xa0f/0x1460 fs/ext4/inode.c:2485 ext4_do_writepages+0x9af/0x3490 fs/ext4/inode.c:2692 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2829 do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:376 __filemap_fdatawrite_range+0xb2/0xf0 mm/filemap.c:419 file_write_and_wait_range+0xca/0x140 mm/filemap.c:794 ext4_sync_file+0x310/0xf10 fs/ext4/fsync.c:154 vfs_fsync_range+0x136/0x220 fs/sync.c:187 __do_sys_msync+0x3cb/0x5c0 mm/msync.c:96 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fba66d8e969 RSP: 002b:00007fba67b1b038 EFLAGS: 00000246 ORIG_RAX: 000000000000001a RAX: ffffffffffffffda RBX: 00007fba66fb6160 RCX: 00007fba66d8e969 RDX: 0000000400000004 RSI: 0180000000000000 RDI: 000000001ffff000 RBP: 00007fba66e10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fba66fb6160 R15: 00007ffc864624f8 INFO: task syz.2.780:10797 blocked for more than 145 seconds. Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.780 state:D stack:26488 pid:10797 tgid:10797 ppid:5829 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 wait_transaction_locked+0x1a1/0x230 fs/jbd2/transaction.c:152 add_transaction_credits+0x110/0xe60 fs/jbd2/transaction.c:222 start_this_handle+0x3e7/0x1410 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x195/0x690 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_dirty_inode+0xa1/0x130 fs/ext4/inode.c:6100 __mark_inode_dirty+0x1eb/0xe50 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2064 inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2335 ext4_page_mkwrite+0x35e/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f97df26f282 RSP: 002b:00007fff54f05950 EFLAGS: 00010202 RAX: 000000000005e008 RBX: 00007f97e00e5720 RCX: 0000000000000000 RDX: 0000001b304c2000 RSI: 0000000000000008 RDI: 00007f97e00e5720 RBP: 0000000000000933 R08: 00007f97de9ff058 R09: 00007f97df5a2000 R10: 00007f97de9ff008 R11: 0000000000000010 R12: ffffffff8b61ffc8 R13: 00007f97df5b6038 R14: 00000000000000d6 R15: fffffffffffa2000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 6 locks held by kworker/u8:2/36: #0: ffff88801c6f3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000ad7d18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88814dc560e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562 #3: ffff88814dc58b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 #4: ffff88814dc5a950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 #5: ffff888078d265d8 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x355/0x1390 fs/ext4/inode.c:705 1 lock held by dhcpcd/5496: #0: ffff88807a794990 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline] #0: ffff88807a794990 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: open_last_lookups fs/namei.c:3799 [inline] #0: ffff88807a794990 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: path_openat+0x88a/0x2d40 fs/namei.c:4036 4 locks held by syz-executor/5819: #0: ffff888032a24088 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814dc56518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff888078d268e8 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] #2: ffff888078d268e8 (mapping.invalidate_lock#2){++++}-{4:4}, at: ext4_page_mkwrite+0x374/0x1750 fs/ext4/inode.c:6223 #3: ffff888078d265d8 (&ei->i_data_sem){++++}-{4:4}, at: ext4_da_map_blocks fs/ext4/inode.c:1814 [inline] #3: ffff888078d265d8 (&ei->i_data_sem){++++}-{4:4}, at: ext4_da_get_block_prep+0x69e/0x11e0 fs/ext4/inode.c:1878 2 locks held by getty/8490: #0: ffff888035a7a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000499b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz.4.776/10746: #0: ffff88814dc58b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 2 locks held by syz.2.780/10797: #0: ffff88803341d308 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814dc56518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 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: 7126 Comm: kworker/u8:20 Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299 Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 RSP: 0018:ffffc90003a8fb28 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8b363fc7 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 000000000000007b R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881249ef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b9de11b970 CR3: 000000000e180000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:869 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0xb98/0x1030 net/batman-adv/network-coding.c:719 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245