INFO: task hwrng:750 blocked for more than 143 seconds. Not tainted 6.7.0-rc5-syzkaller-00230-g3b8a9b2e6809 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:29600 pid:750 tgid:750 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/29: #0: ffffffff8cfab760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8cfab760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8cfab760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 1 lock held by hwrng/750: #0: ffffffff8dbafc68 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:504 2 locks held by udevd/4523: 2 locks held by getty/4826: #0: ffff888025e340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201 2 locks held by syz-executor.1/15923: 3 locks held by syz-executor.2/15970: 3 locks held by kworker/u5:1/15998: #0: ffff8880af8dd938 ((wq_completion)hci11){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2602 #1: ffffc9000df3fd80 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2603 #2: ffff8880b529d108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open+0x22/0x90 net/bluetooth/hci_core.c:481 2 locks held by syz-executor.1/16012: 1 lock held by syz-executor.1/16075: 1 lock held by syz-executor.2/16103: 1 lock held by syz-executor.1/16137: 1 lock held by syz-executor.1/16179: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc5-syzkaller-00230-g3b8a9b2e6809 #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+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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.7.0-rc5-syzkaller-00230-g3b8a9b2e6809 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__sanitizer_cov_trace_switch+0x8/0x90 kernel/kcov.c:317 Code: 00 00 f3 0f 1e fa 48 8b 0c 24 48 89 f2 48 89 fe bf 07 00 00 00 e9 88 fe ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 56 41 55 <41> 54 49 89 fc 55 48 89 f5 53 48 8b 46 08 48 83 f8 20 74 63 77 44 RSP: 0018:ffffc900001076a0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffc90000107790 RCX: 0000000000000001 RDX: ffff888017e4bb80 RSI: ffffffff8ac9d0e0 RDI: 0000000000000002 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000009 R10: 0000000000000005 R11: 0000000000000003 R12: ffffffff8fa359e8 R13: ffffc90000107788 R14: ffffffff8fa359ec R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc921dfed80 CR3: 000000000cd77000 CR4: 0000000000350ef0 Call Trace: unwind_next_frame+0x77d/0x2390 arch/x86/kernel/unwind_orc.c:581 __unwind_start+0x5a4/0x880 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xaf/0x170 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] kmem_cache_free+0xf8/0x350 mm/slub.c:3831 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:1015 __kfree_skb net/core/skbuff.c:1073 [inline] kfree_skb_reason+0x13a/0x210 net/core/skbuff.c:1108 kfree_skb include/linux/skbuff.h:1234 [inline] ieee80211_iface_work+0x387/0xda0 net/mac80211/iface.c:1645 cfg80211_wiphy_work+0x24e/0x330 net/wireless/core.c:437 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 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