INFO: task syz.6.930:8611 blocked for more than 143 seconds. Not tainted 5.15.189-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.930 state:D stack:25600 pid: 8611 ppid: 7588 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500 iterate_supers+0xa4/0x1d0 fs/super.c:716 ksys_sync+0x91/0x150 fs/sync.c:102 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f18f7c06be9 RSP: 002b:00007f18f5e2c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f18f7e2e180 RCX: 00007f18f7c06be9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f18f7e2e180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f18f7e2e218 R14: 00007f18f7e2e180 R15: 00007ffdfbc91558 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/u4:2/154: 2 locks held by getty/3949: #0: ffff88814c79b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4186: #0: ffff8880266d60e0 (&type->s_umount_key#80){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by kworker/0:5/4237: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000425fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/0:6/4256: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900046bfd00 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 1 lock held by syz.6.930/8611: #0: ffff8880266d60e0 (&type->s_umount_key#80){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 2 locks held by syz-executor/8768: #0: ffff888020004918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888020218468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by syz.1.1361/10255: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4416 Comm: kworker/u4:11 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: phy9 ieee80211_iface_work RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline] RIP: 0010:deref_stack_reg+0x4f/0x120 arch/x86/kernel/unwind_orc.c:357 Code: c1 e8 03 42 80 3c 20 00 74 05 e8 3c 91 87 00 4d 8b 6f 08 49 8d 7f 10 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 21 91 87 00 <49> 8b 6f 10 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 92 00 RSP: 0018:ffffc90003107670 EFLAGS: 00000246 RAX: 1ffff92000620eef RBX: ffffc900031077a8 RCX: 0000000000000000 RDX: ffffc900031077a8 RSI: ffffc90003107db8 RDI: ffffc90003107778 RBP: ffffc900031077b0 R08: dffffc0000000000 R09: ffffc900031077b8 R10: fffff52000620ef9 R11: 1ffff92000620ef7 R12: dffffc0000000000 R13: ffffc90003100000 R14: ffffc90003107db8 R15: ffffc90003107768 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a3bf9b2a58 CR3: 00000000509f9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x115d/0x1d90 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3515 kfree_skb include/linux/skbuff.h:1118 [inline] ieee80211_iface_work+0x798/0xc60 net/mac80211/iface.c:1515 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287