INFO: task syz.0.17:6055 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:25496 pid:6055 tgid:6055 ppid:5989 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 request_wait_answer fs/fuse/dev.c:590 [inline] __fuse_request_send fs/fuse/dev.c:604 [inline] __fuse_simple_request+0x12b7/0x1db0 fs/fuse/dev.c:699 fuse_simple_request fs/fuse/fuse_i.h:1264 [inline] fuse_flush+0x66a/0x8a0 fs/fuse/file.c:500 filp_flush+0xbd/0x190 fs/open.c:1469 filp_close+0x1d/0x40 fs/open.c:1482 __range_close fs/file.c:794 [inline] __do_sys_close_range fs/file.c:855 [inline] __se_sys_close_range+0x3d4/0x900 fs/file.c:819 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe97b39c799 RSP: 002b:00007ffd34b41f38 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007ffd34b42020 RCX: 00007fe97b39c799 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000402f3 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32420000 R11: 0000000000000246 R12: 00007ffd34b42060 R13: 00007fe97b615fac R14: 000000000004036c R15: 00007fe97b615fa0 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb5d420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8eb5d420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8eb5d420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by klogd/5200: 2 locks held by getty/5603: #0: ffff888032c1a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5200 Comm: klogd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:_compound_head include/linux/page-flags.h:247 [inline] RIP: 0010:page_slab mm/slab.h:134 [inline] RIP: 0010:virt_to_slab mm/slab.h:168 [inline] RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline] RIP: 0010:qlist_free_all+0x4a/0x100 mm/kasan/quarantine.c:176 Code: 89 ef 4d 89 f4 4d 85 f6 75 42 4c 8b 25 6f 43 21 0c 4c 89 ff e8 27 2b 49 ff 48 c1 e8 06 48 83 e0 c0 49 8d 0c 04 49 8b 44 04 08 <89> c2 83 e2 01 48 ff ca 48 09 c2 48 21 ca 0f b6 42 33 c1 e0 18 3d RSP: 0018:ffffc9000309f758 EFLAGS: 00000206 RAX: ffff888140af88c0 RBX: ffffc9000309f790 RCX: ffffea0001f24b00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88807c92c340 R08: ffff8880b8640d03 R09: 1ffff110170c81a0 R10: dffffc0000000000 R11: ffffed10170c81a1 R12: ffffea0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88807c92c340 FS: 00007f06f4882c80(0000) GS:ffff888124ff2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ee9b31088 CR3: 00000000378d2000 CR4: 00000000003526f0 Call Trace: kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc8/0x760 net/core/skbuff.c:6752 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995 unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2127 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] __sys_sendto+0x672/0x710 net/socket.c:2264 __do_sys_sendto net/socket.c:2271 [inline] __se_sys_sendto net/socket.c:2267 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2267 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06f49d2407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffe82ae9c30 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f06f4882c80 RCX: 00007f06f49d2407 RDX: 000000000000005b RSI: 00007ffe82ae9d70 RDI: 0000000000000003 RBP: 00007ffe82aea1a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffe82aea1b8 R13: 00007ffe82ae9d70 R14: 0000000000000040 R15: 00007ffe82ae9d70