INFO: task syz.8.5084:24080 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.5084 state:D stack:28632 pid:24080 tgid:24079 ppid:18870 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 cgroup_lock_and_drain_offline+0x383/0x800 kernel/cgroup/cgroup.c:3275 cgroup1_get_tree+0xc2/0x1620 kernel/cgroup/cgroup-v1.c:1265 vfs_get_tree+0x92/0x320 fs/super.c:1694 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount fs/namespace.c:3841 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4161 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount fs/namespace.c:4367 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa8bcf9de99 RSP: 002b:00007fa8bdef4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fa8bd225fa0 RCX: 00007fa8bcf9de99 RDX: 00002000000001c0 RSI: 0000200000000140 RDI: 0000000000000000 RBP: 00007fa8bd033eaf R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000c R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa8bd226038 R14: 00007fa8bd225fa0 R15: 00007fffc760d638 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5369: #0: ffff888037d600a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:5/5796: #0: ffff888021ad5140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900053afd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffff88802bebe1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #2: ffff88802bebe1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4a60 drivers/usb/core/hub.c:5899 2 locks held by kworker/u8:15/20398: #0: ffff88801efa4140 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90003e3fd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 1 lock held by syz.3.5711/26262: #0: ffffffff8ebf1af8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 26263 Comm: syz.3.5711 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:__mod_memcg_lruvec_state+0xfc/0x5b0 mm/memcontrol.c:928 Code: 48 8b 44 24 18 49 63 f4 48 8b 88 98 07 00 00 41 80 fc 35 0f 87 67 04 00 00 41 0f b6 c6 4c 8d 34 c5 18 00 00 00 65 4e 01 2c 31 <48> ba 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 f9 48 c1 e9 03 80 RSP: 0018:ffffc90006bcf430 EFLAGS: 00000293 RAX: 000000000000000e RBX: ffff888037fa4200 RCX: 0000607edbe88e00 RDX: 0000000000000002 RSI: 000000000000000e RDI: ffffffff8c401280 RBP: ffff8880358c4c58 R08: 000000008533a977 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 000000000000000e R13: ffffffffffffffff R14: 0000000000000088 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888123ee8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd64c1ed2f8 CR3: 0000000064004000 CR4: 00000000003526f0 Call Trace: mod_memcg_lruvec_state+0x1d0/0x280 mm/memcontrol.c:950 mod_lruvec_state mm/memcontrol.c:973 [inline] lruvec_stat_mod_folio+0x251/0x2e0 mm/memcontrol.c:993 __folio_mod_stat mm/rmap.c:1336 [inline] __folio_remove_rmap mm/rmap.c:1873 [inline] folio_remove_rmap_ptes+0x79a/0xdd0 mm/rmap.c:1900 zap_present_folio_ptes mm/memory.c:1672 [inline] zap_present_ptes mm/memory.c:1730 [inline] do_zap_pte_range mm/memory.c:1832 [inline] zap_pte_range mm/memory.c:1934 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x1e9f/0x4a30 mm/memory.c:2109 unmap_vmas+0x299/0x5f0 mm/memory.c:2178 exit_mmap+0x1ef/0xa00 mm/mmap.c:1300 __mmput+0x12a/0x410 kernel/fork.c:1187 mmput+0x67/0x80 kernel/fork.c:1210 exit_mm kernel/exit.c:615 [inline] do_exit+0x8b1/0x2ae0 kernel/exit.c:997 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efceb99de99 Code: Unable to access opcode bytes at 0x7efceb99de6f. RSP: 002b:00007efcec7d90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007efcebc25fa8 RCX: 00007efceb99de99 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007efcebc25fa8 RBP: 00007efcebc25fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efcebc26038 R14: 00007ffd69667750 R15: 00007ffd69667838