INFO: task syz.4.1872:13361 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1872 state:D stack:25800 pid:13361 ppid:11245 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] iterate_supers+0x80/0x170 fs/super.c:977 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x355/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7faa55d8ebe9 RSP: 002b:00007faa56be0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007faa55fb5fa0 RCX: 00007faa55d8ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102 RBP: 00007faa55e11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faa55fb6038 R14: 00007faa55fb5fa0 R15: 00007ffeef56da98 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5548: #0: ffff88802d1e30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 2 locks held by kworker/1:7/7799: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900034b7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900034b7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 1 lock held by syz-executor/10208: #0: ffff88802d1080e0 (&type->s_umount_key#80){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802d1080e0 (&type->s_umount_key#80){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802d1080e0 (&type->s_umount_key#80){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 1 lock held by syz-executor/13182: #0: ffff88805ca420e0 (&type->s_umount_key#80){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805ca420e0 (&type->s_umount_key#80){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805ca420e0 (&type->s_umount_key#80){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 1 lock held by syz.4.1872/13361: #0: ffff88802d1080e0 (&type->s_umount_key#80){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88802d1080e0 (&type->s_umount_key#80){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz-executor/14143: #0: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #0: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 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+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5851 Comm: kworker/1:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events drain_vmap_area_work RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x10/0x90 kernel/kcov.c:313 Code: 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 15 a0 26 7e 7e <65> 8b 0d a1 26 7e 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 RSP: 0018:ffffc90004f773c8 EFLAGS: 00000246 RAX: ffffffff813acf63 RBX: 1ffff920009eeead RCX: ffff88805d1ebc00 RDX: ffff88805d1ebc00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffff88805d1ebc00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90004f78000 R13: 1ffff920009eeeaf R14: ffffc90004f70000 R15: ffffc90004f77568 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffffd CR3: 00000000306f0000 CR4: 00000000003506e0 Call Trace: on_stack arch/x86/include/asm/stacktrace.h:58 [inline] stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline] deref_stack_reg+0x93/0x240 arch/x86/kernel/unwind_orc.c:403 unwind_next_frame+0x1789/0x2970 arch/x86/kernel/unwind_orc.c:648 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 kasan_depopulate_vmalloc_pte+0x75/0x90 mm/kasan/shadow.c:427 apply_to_pte_range mm/memory.c:2603 [inline] apply_to_pmd_range mm/memory.c:2647 [inline] apply_to_pud_range mm/memory.c:2683 [inline] apply_to_p4d_range mm/memory.c:2719 [inline] __apply_to_page_range+0x84c/0xd50 mm/memory.c:2755 kasan_release_vmalloc+0x97/0xb0 mm/kasan/shadow.c:544 __purge_vmap_area_lazy+0x1640/0x1990 mm/vmalloc.c:1778 drain_vmap_area_work+0x40/0xd0 mm/vmalloc.c:1812 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293