INFO: task hwrng:752 blocked for more than 143 seconds. Not tainted 6.7.0-rc2-syzkaller-00147-gf1a09972a45a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:29704 pid:752 tgid:752 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xedb/0x5af0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe9/0x270 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+0x5b9/0x9d0 kernel/locking/mutex.c:747 hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:504 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 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/28: #0: ffffffff8cfa82e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8cfa82e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8cfa82e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 1 lock held by hwrng/752: #0: ffffffff8dba67e8 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:504 2 locks held by getty/4811: #0: ffff88814c4490a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900020682f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201 3 locks held by kworker/0:2/22353: #0: ffff888013069d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2605 #1: ffffc9000437fd80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2606 #2: ffff88803bcba240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x1bb/0x26e0 drivers/net/netdevsim/fib.c:1489 2 locks held by syz-executor.5/4981: 1 lock held by syz-executor.5/5229: 1 lock held by syz-executor.5/5376: 1 lock held by syz-executor.5/5461: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.7.0-rc2-syzkaller-00147-gf1a09972a45a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 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+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5376 Comm: syz-executor.5 Not tainted 6.7.0-rc2-syzkaller-00147-gf1a09972a45a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x12/0x80 kernel/kcov.c:236 Code: 04 25 00 bd 03 00 48 8b 80 f0 15 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 49 89 d2 49 89 f8 49 89 f1 65 48 8b 14 25 00 bd 03 00 <65> 8b 05 6f 42 7d 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 fc RSP: 0018:ffffc9001a106a18 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff81b9e9c1 RDX: ffff88809d942140 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffffea0002c76c40 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000001 R14: ffffea0002c76c48 R15: dffffc0000000000 FS: 0000555556eac480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb354eaf440 CR3: 000000008a8fe000 CR4: 00000000003506f0 Call Trace: PageTail include/linux/page-flags.h:286 [inline] folio_flags+0x41/0x1f0 include/linux/page-flags.h:313 folio_test_head include/linux/page-flags.h:790 [inline] folio_test_large include/linux/page-flags.h:811 [inline] folio_nr_pages include/linux/mm.h:2048 [inline] scan_folios mm/vmscan.c:4327 [inline] isolate_folios+0xa82/0x3f50 mm/vmscan.c:4456 evict_folios+0x1a2/0x1b90 mm/vmscan.c:4487 try_to_shrink_lruvec+0x769/0xb00 mm/vmscan.c:4678 lru_gen_shrink_lruvec mm/vmscan.c:4817 [inline] shrink_lruvec+0x314/0x2990 mm/vmscan.c:5592 shrink_node_memcgs mm/vmscan.c:5812 [inline] shrink_node+0x807/0x3790 mm/vmscan.c:5847 shrink_zones mm/vmscan.c:6086 [inline] do_try_to_free_pages+0x36c/0x1940 mm/vmscan.c:6148 try_to_free_mem_cgroup_pages+0x31a/0x770 mm/vmscan.c:6463 try_charge_memcg+0x3d3/0x11f0 mm/memcontrol.c:2742 try_charge mm/memcontrol.c:2884 [inline] charge_memcg mm/memcontrol.c:7210 [inline] __mem_cgroup_charge+0xa6/0x140 mm/memcontrol.c:7225 mem_cgroup_charge include/linux/memcontrol.h:684 [inline] __filemap_add_folio+0x88c/0xed0 mm/filemap.c:854 filemap_add_folio+0xb1/0x1e0 mm/filemap.c:937 page_cache_ra_unbounded+0x1d0/0x5f0 mm/readahead.c:250 do_page_cache_ra mm/readahead.c:299 [inline] page_cache_ra_order+0x72b/0xa80 mm/readahead.c:546 do_sync_mmap_readahead mm/filemap.c:3141 [inline] filemap_fault+0x16a8/0x3570 mm/filemap.c:3233 __do_fault+0x107/0x600 mm/memory.c:4265 do_cow_fault mm/memory.c:4662 [inline] do_fault mm/memory.c:4764 [inline] do_pte_missing mm/memory.c:3730 [inline] handle_pte_fault mm/memory.c:5038 [inline] __handle_mm_fault+0x3a8d/0x3d70 mm/memory.c:5179 handle_mm_fault+0x47a/0xa10 mm/memory.c:5344 do_user_addr_fault+0x3d1/0x1000 arch/x86/mm/fault.c:1413 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5d/0xc0 arch/x86/mm/fault.c:1561 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7f383a22b1b3 Code: 48 85 c0 74 1b 48 83 f8 01 0f 85 3b 03 00 00 0f b7 44 24 18 66 c1 c0 08 0f b7 c0 48 89 44 24 18 48 8b 44 24 10 0f b7 54 24 18 <66> 89 10 e9 82 fe ff ff 48 83 3c 24 08 0f 85 a1 02 00 00 48 8b 44 RSP: 002b:00007ffd8c89a2c0 EFLAGS: 00010246 RAX: 0000000020000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 000000000000000a RSI: 0000000000000000 RDI: 0000555556eac360 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 000000008171f047 R11: 0000000000000246 R12: 00007f3839e004e0 R13: fffffffffffffffe R14: 00007f3839e00000 R15: 00007f3839e004e8