INFO: task hwrng:755 blocked for more than 143 seconds. Not tainted 6.7.0-syzkaller-00119-g5db8752c3b81 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:26520 pid:755 tgid:755 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a3/0xd60 kernel/locking/mutex.c:747 hwrng_fillfn+0xe6/0x3c0 drivers/char/hw_random/core.c:504 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 1 lock held by hwrng/755: #0: ffffffff8e0e0e88 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0xe6/0x3c0 drivers/char/hw_random/core.c:504 2 locks held by getty/4822: #0: ffff888029cba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by syz-executor.0/5089: #0: ffff888090f9a348 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x258/0x320 fs/file.c:1191 #1: ffff88803df42c00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: iterate_dir+0x436/0x6f0 fs/readdir.c:103 #2: ffff88802a24c420 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2436 [inline] #2: ffff88802a24c420 (sb_writers#4){.+.+}-{0:0}, at: iterate_dir+0x5d9/0x6f0 fs/readdir.c:113 3 locks held by syz-executor.5/2709: 1 lock held by syz-executor.5/2715: 2 locks held by syz-executor.5/6407: 2 locks held by syz-executor.2/6409: #0: ffff88802a24c420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88803b114a00 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline] #1: ffff88803b114a00 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x260/0x530 fs/namei.c:3872 2 locks held by syz-executor.4/6410: #0: ffff88802a24c420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff888043637200 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline] #1: ffff888043637200 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x260/0x530 fs/namei.c:3872 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-syzkaller-00119-g5db8752c3b81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6407 Comm: syz-executor.5 Not tainted 6.7.0-syzkaller-00119-g5db8752c3b81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline] RIP: 0010:deref_stack_reg+0x46/0x250 arch/x86/kernel/unwind_orc.c:403 Code: 00 00 00 fc ff df e8 89 9c 50 00 48 8d 6b 08 49 89 ec 49 c1 ec 03 43 80 3c 3c 00 74 08 48 89 ef e8 af a2 ac 00 48 89 6c 24 10 <4c> 89 74 24 18 48 8b 43 08 48 89 44 24 20 48 8d 6b 10 49 89 ed 49 RSP: 0018:ffffc90014476d88 EFLAGS: 00000246 RAX: ffffffff813deb57 RBX: ffffc90014476ec0 RCX: 0000000000040000 RDX: ffffc90014951000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90014476ec8 R08: 0000000000000005 R09: ffffffff813dd790 R10: 0000000000000003 R11: ffff88807c673b80 R12: 1ffff9200288edd9 R13: dffffc0000000000 R14: ffffc90014476f00 R15: dffffc0000000000 FS: 00007effe1e086c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fef6cb00ee4 CR3: 000000008dee4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x1ab9/0x29e0 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x146/0x1a0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x117/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] kmem_cache_free+0x299/0x470 mm/slub.c:3831 free_buffer_head+0x55/0x240 fs/buffer.c:3034 try_to_free_buffers+0x311/0x5f0 fs/buffer.c:2975 block_invalidate_folio+0x4b3/0x5e0 fs/buffer.c:1633 folio_invalidate mm/truncate.c:158 [inline] truncate_cleanup_folio+0x106/0x3d0 mm/truncate.c:178 truncate_inode_pages_range+0x2b6/0xf70 mm/truncate.c:367 __jbd2_journal_erase fs/jbd2/journal.c:2011 [inline] jbd2_journal_flush+0x735/0xc40 fs/jbd2/journal.c:2483 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1099 [inline] __ext4_ioctl fs/ext4/ioctl.c:1607 [inline] ext4_ioctl+0x33a5/0x5540 fs/ext4/ioctl.c:1627 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7effe107cd29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007effe1e080c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007effe11abf80 RCX: 00007effe107cd29 RDX: 0000000020000140 RSI: 000000004004662b RDI: 0000000000000003 RBP: 00007effe10c947a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007effe11abf80 R15: 00007fffed59e5b8