INFO: task syz-executor:5854 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22104 pid:5854 tgid:5854 ppid:5853 task_flags:0x440100 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 io_schedule+0xbf/0x130 kernel/sched/core.c:7903 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:250 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x1320 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:242 ext4_reserve_inode_write+0x1be/0x340 fs/ext4/inode.c:6326 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6501 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6538 __mark_inode_dirty+0x1ee/0xe40 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2063 inode_update_time fs/inode.c:2076 [inline] __file_update_time fs/inode.c:2304 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2334 ext4_page_mkwrite+0x33d/0x1880 fs/ext4/inode.c:6704 do_page_mkwrite+0x171/0x380 mm/memory.c:3361 wp_page_shared mm/memory.c:3762 [inline] do_wp_page+0xb10/0x4f00 mm/memory.c:3981 handle_pte_fault mm/memory.c:6068 [inline] __handle_mm_fault+0x1b2d/0x2a50 mm/memory.c:6195 handle_mm_fault+0x589/0xd10 mm/memory.c:6364 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f84844781ff RSP: 002b:00007ffc2bff1090 EFLAGS: 00010202 RAX: 00007f8482c88000 RBX: 0000555585f13860 RCX: 0000000000000003 RDX: 1ffffffff047125b RSI: 0000555585f1f908 RDI: 0000000000000008 RBP: 00007ffc2bff1380 R08: 0000555585f1f908 R09: 000000000000224b R10: 0000000000000001 R11: 00007ffc2bff1590 R12: 00007ffc2bff13e0 R13: 0000000000000004 R14: 00007ffc2bff1100 R15: 00007ffc2bff11d0 INFO: task kworker/u8:42:20084 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:42 state:D stack:24408 pid:20084 tgid:20084 ppid:2 task_flags:0x4248060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 io_schedule+0xbf/0x130 kernel/sched/core.c:7903 rq_qos_wait+0x22f/0x340 block/blk-rq-qos.c:307 __wbt_wait block/blk-wbt.c:596 [inline] wbt_wait+0x1af/0x390 block/blk-wbt.c:656 __rq_qos_throttle+0x56/0xa0 block/blk-rq-qos.c:66 rq_qos_throttle block/blk-rq-qos.h:168 [inline] rq_qos_throttle block/blk-rq-qos.h:163 [inline] blk_mq_get_new_requests block/blk-mq.c:3033 [inline] blk_mq_submit_bio+0x2174/0x2a10 block/blk-mq.c:3183 __submit_bio+0x3cf/0x690 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:753 submit_bio_noacct+0xb49/0x1ed0 block/blk-core.c:876 ext4_io_submit fs/ext4/page-io.c:404 [inline] io_submit_add_bh fs/ext4/page-io.c:445 [inline] ext4_bio_write_folio+0x756/0x1dc0 fs/ext4/page-io.c:589 mpage_process_page_bufs+0x47c/0x8d0 fs/ext4/inode.c:2191 mpage_prepare_extent_to_map+0x79f/0x14d0 fs/ext4/inode.c:2736 ext4_do_writepages+0xa11/0x3cf0 fs/ext4/inode.c:2877 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3025 do_writepages+0x27a/0x600 mm/page-writeback.c:2634 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x60d/0xfa0 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_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0x748/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:14788 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:23304 pid:14788 tgid:14788 ppid:14733 task_flags:0x440140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 io_schedule+0xbf/0x130 kernel/sched/core.c:7903 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:250 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x1320 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:242 __ext4_new_inode+0x17db/0x4f00 fs/ext4/ialloc.c:1132 ext4_mkdir+0x283/0xb80 fs/ext4/namei.c:3007 vfs_mkdir+0x590/0x8c0 fs/namei.c:4366 do_mkdirat+0x304/0x3e0 fs/namei.c:4399 __do_sys_mkdirat fs/namei.c:4416 [inline] __se_sys_mkdirat fs/namei.c:4414 [inline] __x64_sys_mkdirat+0x83/0xb0 fs/namei.c:4414 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f940e98d617 RSP: 002b:00007ffc74373878 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f940ea123a5 RCX: 00007f940e98d617 RDX: 00000000000001ff RSI: 00007f940ea123a5 RDI: 00000000ffffff9c RBP: 00007f940ebe67b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 INFO: task syz.7.6439:15036 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.6439 state:D stack:27672 pid:15036 tgid:15011 ppid:10063 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 io_schedule+0xbf/0x130 kernel/sched/core.c:7903 folio_wait_bit_common+0x3d6/0x9e0 mm/filemap.c:1317 folio_wait_writeback+0x3c/0x90 mm/page-writeback.c:3124 __filemap_fdatawait_range+0x11f/0x200 mm/filemap.c:539 file_write_and_wait_range+0x101/0x140 mm/filemap.c:798 ext4_sync_file+0x310/0xf10 fs/ext4/fsync.c:154 vfs_fsync_range+0x139/0x220 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/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f536698eec9 RSP: 002b:00007f536777a038 EFLAGS: 00000246 ORIG_RAX: 000000000000001a RAX: ffffffffffffffda RBX: 00007f5366be6360 RCX: 00007f536698eec9 RDX: 0000000400000004 RSI: 01800000ff000000 RDI: 000000001ffff000 RBP: 00007f5366a11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5366be63f8 R14: 00007f5366be6360 R15: 00007ffc519a7a88 INFO: task dhcpcd:15027 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:25976 pid:15027 tgid:15027 ppid:5531 task_flags:0x400040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 io_schedule+0xbf/0x130 kernel/sched/core.c:7903 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:250 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:67 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:420 [inline] __ext4_get_inode_loc+0x1085/0x1540 fs/ext4/inode.c:4961 ext4_get_inode_loc+0xbd/0x160 fs/ext4/inode.c:4994 ext4_xattr_ibody_get+0x106/0x4b0 fs/ext4/xattr.c:644 ext4_xattr_get+0x165/0x780 fs/ext4/xattr.c:705 __vfs_getxattr+0x13a/0x1a0 fs/xattr.c:423 get_vfs_caps_from_disk+0x140/0x550 security/commoncap.c:684 get_file_caps security/commoncap.c:775 [inline] cap_bprm_creds_from_file+0x66b/0x1cd0 security/commoncap.c:921 security_bprm_creds_from_file+0x1e3/0x210 security/security.c:1285 bprm_creds_from_file fs/exec.c:1595 [inline] begin_new_exec+0x11c/0x38b0 fs/exec.c:1105 load_elf_binary+0x8e7/0x4fe0 fs/binfmt_elf.c:995 search_binary_handler fs/exec.c:1670 [inline] exec_binprm fs/exec.c:1702 [inline] bprm_execve fs/exec.c:1754 [inline] bprm_execve+0x8bb/0x1640 fs/exec.c:1730 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1860 do_execve fs/exec.c:1934 [inline] __do_sys_execve fs/exec.c:2010 [inline] __se_sys_execve fs/exec.c:2005 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2005 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f352c05b107 RSP: 002b:00007f352bec4e68 EFLAGS: 00000202 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007ffe3dd39010 RCX: 00007f352c05b107 RDX: 000055613a510ae0 RSI: 00007ffe3dd39200 RDI: 000055612c4276bd RBP: 00007f352bec4ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000001 R13: 00007ffe3dd38cf0 R14: 00007f352bec4f20 R15: 0000000000000040 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by syz-executor/5854: #0: ffff8880750141c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11b/0x530 mm/mmap_lock.c:147 #1: ffff888034f7a520 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3361 #2: ffff888034f7e950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 4 locks held by kworker/u8:42/20084: #0: ffff888140aad148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003d4fd10 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888034f7a0e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:563 #3: ffff888034f7cb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x27a/0x600 mm/page-writeback.c:2634 2 locks held by getty/25529: #0: ffff888034b0e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032242f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz-executor/14788: #0: ffff888034f7a428 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10e/0x4a0 fs/namei.c:4132 #1: ffff88805bd46380 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:915 [inline] #1: ffff88805bd46380 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1bb/0x4a0 fs/namei.c:4139 #2: ffff888034f7e950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 2 locks held by dhcpcd/15027: #0: ffff8880317ddd08 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1361 [inline] #0: ffff8880317ddd08 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xa4/0x1640 fs/exec.c:1734 #1: ffff888033153098 (&ei->xattr_sem){.+.+}-{4:4}, at: ext4_xattr_get+0x14d/0x780 fs/ext4/xattr.c:704 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245