syzbot

INFO: task syz.8.4586:22675 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.8.4586      state:D stack:27384 pid:22675 tgid:22670 ppid:11116  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 cgroup_lock_and_drain_offline+0x51a/0x650 kernel/cgroup/cgroup.c:3275
 cgroup1_get_tree+0x9d/0x890 kernel/cgroup/cgroup-v1.c:1265
 vfs_get_tree+0x92/0x2a0 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1a3259de59
RSP: 002b:00007f1a33509028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1a32826090 RCX: 00007f1a3259de59
RDX: 0000200000000640 RSI: 0000200000000600 RDI: 0000000000000000
RBP: 00007f1a32633e6f R08: 00002000000003c0 R09: 0000000000000000
R10: 0000000002208000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1a32826128 R14: 00007f1a32826090 R15: 00007fff59f83928
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/32:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5376:
 #0: ffff888036a0f0a0 (&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+0x45a/0x1360 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/17569:
4 locks held by syz.2.5486/25866:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 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:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5950 Comm: kworker/u8:11 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Workqueue: krds_cp_wq#12/0 rds_connect_worker
RIP: 0010:qlink_to_object mm/kasan/quarantine.c:140 [inline]
RIP: 0010:qlink_free mm/kasan/quarantine.c:145 [inline]
RIP: 0010:qlist_free_all+0x77/0x100 mm/kasan/quarantine.c:179
Code: e2 01 48 ff ca 48 09 c2 48 21 ca 0f b6 42 33 c1 e0 18 3d 00 00 00 f5 49 0f 45 d5 4c 8b 62 08 49 8b 2f 49 63 84 24 b8 00 00 00 <49> 29 c7 4c 89 e7 4c 89 fe e8 5b e4 ff ff 66 90 48 8d 15 00 00 00
RSP: 0018:ffffc90004c57750 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90004c57788 RCX: ffffea0001767d00
RDX: ffffea0001767d00 RSI: ffffffff8e22a444 RDI: ffff88805d9f4000
RBP: ffff8880536ead80 R08: ffffffff905776f7 R09: 1ffffffff20aeede
R10: dffffc0000000000 R11: fffffbfff20aeedf R12: ffff888142eec140
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88805d9f4000
FS:  0000000000000000(0000) GS:ffff888125058000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff4c860da0 CR3: 000000000e946000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 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:4612 [inline]
 slab_alloc_node mm/slub.c:4945 [inline]
 kmem_cache_alloc_lru_noprof+0x2aa/0x5f0 mm/slub.c:4978
 sock_alloc_inode+0x2c/0x1a0 net/socket.c:330
 alloc_inode+0x6a/0x1b0 fs/inode.c:338
 new_inode_pseudo include/linux/fs.h:3024 [inline]
 sock_alloc net/socket.c:685 [inline]
 __sock_create+0x12d/0x9d0 net/socket.c:1615
 rds_tcp_conn_path_connect+0x2d8/0x920 net/rds/tcp_connect.c:-1
 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>