INFO: task syz.2.360:7447 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.360 state:D stack:24536 pid:7447 tgid:7446 ppid:7277 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7048 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 __super_lock fs/super.c:57 [inline] super_lock+0x25c/0x3b0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f84a258f749 RSP: 002b:00007f84a338b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f84a27e5fa0 RCX: 00007f84a258f749 RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000200 RBP: 00007f84a2613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f84a27e6038 R14: 00007f84a27e5fa0 R15: 00007fff570fb758 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e13efa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e13efa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e13efa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/50: #0: ffff8880b863ab98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:652 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by getty/5581: #0: ffff88814d63d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5822: 3 locks held by syz-executor/6691: 3 locks held by syz-executor/6699: 1 lock held by syz.2.360/7447: #0: ffff88807aa840e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807aa840e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:121 1 lock held by syz.7.571/8451: ============================================= 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 10/25/2025 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:161 [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:375 [inline] watchdog+0xe88/0xee0 kernel/hung_task.c:588 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5182 Comm: klogd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_try_cmpxchg128 arch/x86/include/asm/cmpxchg_64.h:83 [inline] RIP: 0010:__update_freelist_fast mm/slub.c:767 [inline] RIP: 0010:slab_update_freelist mm/slub.c:832 [inline] RIP: 0010:__slab_free+0x199/0x320 mm/slub.c:5957 Code: 24 10 0f 85 85 00 00 00 f3 90 e9 c6 fe ff ff 45 31 e4 41 f6 47 22 20 0f 84 63 ff ff ff 48 89 de 48 8b 5c 24 40 48 8b 4c 24 48 <48> 8b 44 24 50 48 8b 54 24 58 f0 48 0f c7 4e 20 48 89 f3 74 4e 48 RSP: 0018:ffffc900030d7660 EFLAGS: 00000202 RAX: 000000000010000d RBX: ffff888077d29000 RCX: 000000000010000d RDX: ffff888077d29000 RSI: ffffea0001df4a00 RDI: 0000000000000000 RBP: ffffc900030d7700 R08: 0000000000000000 R09: ffffffff8227a82c R10: dffffc0000000000 R11: fffffbfff1f44b6f R12: 0000000000000000 R13: ffff888077d28800 R14: 000000000010000e R15: ffff88813fea6dc0 FS: 00007f413566ec80(0000) GS:ffff888125c07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe4cc0ae38 CR3: 000000007d91a000 CR4: 00000000003526f0 Call Trace: qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 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:4969 [inline] slab_alloc_node mm/slub.c:5283 [inline] kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5335 __alloc_skb+0x1dc/0x3a0 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6714 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995 unix_dgram_sendmsg+0x454/0x1840 net/unix/af_unix.c:2130 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ce/0x540 net/socket.c:2221 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f41357be407 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:00007ffddfd92ef0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f413566ec80 RCX: 00007f41357be407 RDX: 0000000000000046 RSI: 00007ffddfd93030 RDI: 0000000000000003 RBP: 00007ffddfd93460 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffddfd93478 R13: 00007ffddfd93030 R14: 000000000000002b R15: 00007ffddfd93030