INFO: task kworker/u8:16:8187 blocked for more than 143 seconds. Not tainted 6.12.0-syzkaller-03657-g43fb83c17ba2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:16 state:D stack:23888 pid:8187 tgid:8187 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe5a/0x5ae0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 io_schedule+0xbf/0x130 kernel/sched/core.c:7681 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+0xda/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:426 [inline] do_get_write_access+0x8c3/0x1270 fs/jbd2/transaction.c:972 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1245 __ext4_journal_get_write_access+0x6a/0x390 fs/ext4/ext4_jbd2.c:239 ext4_mb_mark_context+0x176/0xdb0 fs/ext4/mballoc.c:4003 ext4_mb_mark_diskspace_used+0x467/0x8c0 fs/ext4/mballoc.c:4133 ext4_mb_new_blocks+0xa33/0x4e80 fs/ext4/mballoc.c:6235 ext4_ext_map_blocks+0x1bca/0x5a30 fs/ext4/extents.c:4379 ext4_map_create_blocks fs/ext4/inode.c:516 [inline] ext4_map_blocks+0x457/0x1370 fs/ext4/inode.c:702 mpage_map_one_extent fs/ext4/inode.c:2219 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2272 [inline] ext4_do_writepages+0x198c/0x32f0 fs/ext4/inode.c:2735 ext4_writepages+0x303/0x730 fs/ext4/inode.c:2824 do_writepages+0x1b3/0x820 mm/page-writeback.c:2683 __writeback_single_inode+0x166/0xfa0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x603/0xfa0 fs/fs-writeback.c:1976 __writeback_inodes_wb+0xff/0x2e0 fs/fs-writeback.c:2047 wb_writeback+0x72d/0xb60 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+0x741/0xbc0 fs/fs-writeback.c:2343 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by ksoftirqd/0/16: #0: ffff8880b863ef18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598 1 lock held by khungtaskd/30: #0: ffffffff8ddba680 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddba680 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddba680 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 2 locks held by getty/5606: #0: ffff888035b520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 6 locks held by kworker/u8:16/8187: #0: ffff88801decc948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204 #1: ffffc9000302fd80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 #2: ffff88802f3840e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562 #3: ffff88802f386b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b3/0x820 mm/page-writeback.c:2683 #4: ffff888034d90958 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448 #5: ffff888078928288 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x352/0x1370 fs/ext4/inode.c:701 3 locks held by syz-executor/8269: #0: ffff88802f384420 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10d/0x530 fs/namei.c:4073 #1: ffff888079fd97c8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff888079fd97c8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1c2/0x530 fs/namei.c:4080 #2: ffff888034d90958 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xf6c/0x1430 fs/jbd2/transaction.c:448 2 locks held by syz.1.540/8548: #0: ffff8880256f8420 (sb_writers#5){.+.+}-{0:0}, at: get_signal+0x23f3/0x2610 kernel/signal.c:3001 #1: ffff888027a18ba0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline] #1: ffff888027a18ba0 (&mm->mmap_lock){++++}-{4:4}, at: __get_user_pages_locked mm/gup.c:1726 [inline] #1: ffff888027a18ba0 (&mm->mmap_lock){++++}-{4:4}, at: get_dump_page+0xb6/0x220 mm/gup.c:2269 4 locks held by syz.1.669/9054: #0: ffff88802539d070 (&vma->vm_lock->lock){++++}-{4:4}, at: vma_start_read include/linux/mm.h:716 [inline] #0: ffff88802539d070 (&vma->vm_lock->lock){++++}-{4:4}, at: lock_vma_under_rcu+0x13e/0x980 mm/memory.c:6243 #1: ffff88802f384518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x177/0x380 mm/memory.c:3162 #2: ffff888078928598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:873 [inline] #2: ffff888078928598 (mapping.invalidate_lock){++++}-{4:4}, at: ext4_page_mkwrite+0x37e/0x1760 fs/ext4/inode.c:6161 #3: ffff888078928288 (&ei->i_data_sem){++++}-{4:4}, at: ext4_da_map_blocks fs/ext4/inode.c:1809 [inline] #3: ffff888078928288 (&ei->i_data_sem){++++}-{4:4}, at: ext4_da_get_block_prep+0x6a0/0x11e0 fs/ext4/inode.c:1873 2 locks held by syz-executor/9127: #0: ffff88802f384420 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10d/0x530 fs/namei.c:4073 #1: ffff888079fd97c8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff888079fd97c8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1c2/0x530 fs/namei.c:4080 2 locks held by syz-executor/9231: #0: ffff88802f384420 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10d/0x530 fs/namei.c:4073 #1: ffff888079fd97c8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff888079fd97c8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1c2/0x530 fs/namei.c:4080 5 locks held by sed/9501: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller-03657-g43fb83c17ba2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 6194 Comm: kworker/u8:13 Not tainted 6.12.0-syzkaller-03657-g43fb83c17ba2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:memset_orig+0x84/0xb0 arch/x86/lib/memset_64.S:100 Code: 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 66 0f 1f 44 00 00 ff c9 48 89 07 48 8d 7f 08 75 f5 83 e2 07 74 0a ff ca 88 07 <48> 8d 7f 01 75 f6 4c 89 d0 c3 cc cc cc cc 48 83 fa 07 76 e3 48 89 RSP: 0018:ffffc9000494fb50 EFLAGS: 00000206 RAX: fbfbfbfbfbfbfbfb RBX: ffff88807ba238c0 RCX: 0000000000000000 RDX: 0000000000000005 RSI: 00000000000000fb RDI: ffffed100f744730 RBP: ffff888141ab8780 R08: 0000000000000140 R09: 0000000000000000 R10: ffffed100f744718 R11: 0000000000000004 R12: ffff888141ab8780 R13: 0000000000000000 R14: ffffea0001ee88c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcfc50dd440 CR3: 000000000db7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x46/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x152/0x4b0 mm/slub.c:4681 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1148 __kfree_skb net/core/skbuff.c:1205 [inline] consume_skb net/core/skbuff.c:1436 [inline] consume_skb+0xcc/0x100 net/core/skbuff.c:1430 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x878/0xc90 drivers/net/netdevsim/dev.c:851 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244