INFO: task syz-executor:4279 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21840 pid:4279 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797 folio_wait_bit_common+0x6e1/0xf60 mm/filemap.c:1324 __filemap_get_folio+0x406/0xdd0 mm/filemap.c:1959 truncate_inode_pages_range+0x3a6/0xff0 mm/truncate.c:377 evict+0x498/0x870 fs/inode.c:707 dispose_list fs/inode.c:738 [inline] evict_inodes+0x604/0x690 fs/inode.c:792 generic_shutdown_super+0x93/0x340 fs/super.c:480 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f236d58ff17 RSP: 002b:00007ffe1093a168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f236d611c05 RCX: 00007f236d58ff17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe1093a220 RBP: 00007ffe1093a220 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe1093b2b0 R13: 00007f236d611c05 R14: 000000000003cfcb R15: 00007ffe1093b2f0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b370 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bb90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/29: #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4028: #0: ffff88814d6f8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/4279: #0: ffff888058b520e0 (&type->s_umount_key#109){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 2 locks held by kworker/u4:5/4295: ============================================= NMI backtrace for cpu 1 CPU: 1 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+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:357 [inline] RIP: 0010:unwind_next_frame+0xa25/0x20b0 arch/x86/kernel/unwind_orc.c:539 Code: 0f b6 04 01 84 c0 0f 85 84 11 00 00 83 3b 00 0f 95 c0 49 39 ee 0f 96 c1 20 c1 49 39 ef 0f 97 c0 20 c8 3c 01 75 18 48 8d 45 08 <4c> 39 f0 0f 97 c1 4c 39 f8 0f 96 c0 84 c1 0f 85 c9 00 00 00 48 8d RSP: 0018:ffffc90000146f70 EFLAGS: 00000246 RAX: ffffc90000147b20 RBX: ffffc90000147048 RCX: 1ffff92000028e01 RDX: ffffc90000147b20 RSI: ffffffff8e7f9eac RDI: 0000000000000001 RBP: ffffc90000147b18 R08: 000000000000000a R09: 000000000000000a R10: fffff52000028e15 R11: 1ffff92000028e13 R12: 1ffff92000028e0a R13: 1ffff92000028e0b R14: ffffc90000140000 R15: ffffc90000148000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f539912f8 CR3: 0000000026e0e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422 __skb_ext_alloc net/core/skbuff.c:6475 [inline] skb_ext_add+0x141/0x910 net/core/skbuff.c:6578 nf_bridge_alloc include/net/netfilter/br_netfilter.h:12 [inline] br_nf_pre_routing_ipv6+0x131/0x670 net/bridge/br_netfilter_ipv6.c:231 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_bridge_pre net/bridge/br_input.c:260 [inline] br_handle_frame+0x919/0x12f0 net/bridge/br_input.c:406 __netif_receive_skb_core+0xfc5/0x3840 net/core/dev.c:5475 __netif_receive_skb_one_core net/core/dev.c:5579 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5695 process_backlog+0x37c/0x6e0 net/core/dev.c:6023 __napi_poll+0xc0/0x460 net/core/dev.c:6590 napi_poll net/core/dev.c:6657 [inline] net_rx_action+0x5b1/0xad0 net/core/dev.c:6771 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 run_ksoftirqd+0x98/0xf0 kernel/softirq.c:963 smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295