INFO: task syz-executor:4261 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:21456 pid:4261 ppid:4260 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2500 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 wp_page_shared+0x167/0x370 mm/memory.c:3358 handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fede0b6d155 RSP: 002b:00007ffc53e85458 EFLAGS: 00010203 RAX: 00007feddb600000 RBX: 000055556fe82240 RCX: 00007feddb600000 RDX: 00007feddb601584 RSI: 000055556fe8f2b0 RDI: 00007feddb600fa0 RBP: 00007ffc53e85470 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055556fe874d0 R13: 0000000000000008 R14: 0000000000000001 R15: 0000000000000000 INFO: task syz-executor:5688 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:22384 pid:5688 ppid:5663 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 __ext4_new_inode+0x30a2/0x3b40 fs/ext4/ialloc.c:1350 ext4_mkdir+0x407/0xc90 fs/ext4/namei.c:3068 vfs_mkdir+0x386/0x570 fs/namei.c:4157 do_mkdirat+0x1d8/0x440 fs/namei.c:4182 __do_sys_mkdirat fs/namei.c:4197 [inline] __se_sys_mkdirat fs/namei.c:4195 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4195 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f872079cfc7 RSP: 002b:00007ffddaef9a38 EFLAGS: 00000206 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f8720834aaf RCX: 00007f872079cfc7 RDX: 00000000000001ff RSI: 00007f8720834aaf RDI: 00000000ffffff9c RBP: 00007f8720a267b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffddaef9ca8 R15: 0000000000000000 INFO: task syz.1.574:5866 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.574 state:D stack:26288 pid:5866 ppid:4274 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2500 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x199c/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7efc146727a9 RSP: 002b:00007ffcd09f0450 EFLAGS: 00010202 RAX: 0000001b2ff1e000 RBX: ffffffff862aaee8 RCX: 0000001b2ff1dff8 RDX: 0000001b2f924220 RSI: 0000000000000008 RDI: 00007efc15555720 RBP: 000000000000015c R08: 00007efc14a10000 R09: 00007efc14a12000 R10: 00000000862aaeec R11: 00000000000000ff R12: 00007efc14a25f40 R13: 000000000000035b R14: ffffffff862aab9a R15: 00007efc15555720 INFO: task syz.0.580:5884 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.580 state:D stack:26288 pid:5884 ppid:4273 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2500 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x199c/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f0d24e727a9 RSP: 002b:00007ffd2f090be0 EFLAGS: 00010202 RAX: 0000001b2fe24000 RBX: ffffffff81ea97c6 RCX: 0000001b2fe23ff8 RDX: 00000000005ffde8 RSI: 00000000005ffde8 RDI: 00007f0d25d55700 RBP: 0000000000000001 R08: 0000000000000000 R09: 00007f0d25212000 R10: 00007f0d25d55700 R11: 0000000000000000 R12: 00007f0d25226038 R13: 0000000000000000 R14: ffffffff81ea9eac R15: 00007f0d25d55720 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e170 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2e990 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6529 6 locks held by kworker/u4:4/76: #0: ffff8881401e9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc900015d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff88807e17e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415 #3: ffff88807e180c18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717 #4: ffff88807e182990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 #5: ffff8880747534b0 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674 2 locks held by getty/4030: #0: ffff88802f62a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 3 locks held by syz-executor/4261: #0: ffff88807686f958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807686f958 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff88807686f958 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88807e182990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 2 locks held by kworker/u4:7/4351: 3 locks held by syz-executor/5688: #0: ffff88807e17e460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff88807464c030 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:799 [inline] #1: ffff88807464c030 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3927 #2: ffff88807e182990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 3 locks held by syz.1.574/5866: #0: ffff8880793708d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff8880793708d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff8880793708d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88807e182990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 3 locks held by syz.0.580/5884: #0: ffff888079377958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff888079377958 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff888079377958 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88807e17e558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88807e182990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:rcu_is_watching+0x63/0xa0 kernel/rcu/tree.c:722 Code: 89 f7 e8 90 4d 67 00 48 c7 c3 c8 57 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 2f 8b 03 65 ff 0d 15 45 96 7e <74> 0c 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 e8 32 59 94 ff eb ed 48 RSP: 0018:ffffc90000b77740 EFLAGS: 00000082 RAX: 0000000000063684 RBX: ffff8880b8e357c8 RCX: d0b5c99395346d00 RDX: 0000000000000000 RSI: ffffffff8adf6880 RDI: ffffffff8adf6840 RBP: ffffc90000b77870 R08: ffffffff8e20b46f R09: 1ffffffff1c4168d R10: dffffc0000000000 R11: fffffbfff1c4168e R12: 1ffff9200016ef18 R13: dffffc0000000000 R14: ffffffff8c664980 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005578822ba168 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xcf/0x920 kernel/locking/lockdep.c:5689 local_lock_release include/linux/local_lock_internal.h:38 [inline] crng_make_state+0x4d8/0xb00 drivers/char/random.c:353 _get_random_bytes+0xfc/0x250 drivers/char/random.c:366 eth_random_addr include/linux/etherdevice.h:232 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:755 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x2e5/0xa80 drivers/net/netdevsim/dev.c:851 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295