syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5096/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=6349, q=6 ncpus=2)
task:syz-executor380 state:R  running task     stack:25072 pid:5096  tgid:5096  ppid:5093   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x17d1/0x49f0 kernel/sched/core.c:6727
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7047
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:348
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:lock_acquire+0x25a/0x530 kernel/locking/lockdep.c:5758
Code: 2b 00 74 08 4c 89 f7 e8 c4 78 84 00 f6 44 24 61 02 0f 85 8e 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000450ed00 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920008a1dac RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8baac7e0 RDI: ffffffff8bfe6de0
RBP: ffffc9000450ee48 R08: ffffffff92c8d427 R09: 1ffffffff2591a84
R10: dffffc0000000000 R11: fffffbfff2591a85 R12: 1ffff920008a1da8
R13: dffffc0000000000 R14: ffffc9000450ed60 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 rcu_read_lock include/linux/rcupdate.h:750 [inline]
 is_bpf_text_address+0x42/0x2b0 kernel/bpf/core.c:762
 kernel_text_address+0xa7/0xe0 kernel/extable.c:125
 __kernel_text_address+0xd/0x40 kernel/extable.c:79
 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369
 arch_stack_walk+0x124/0x1b0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x117/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:314 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3813 [inline]
 slab_alloc_node mm/slub.c:3860 [inline]
 kmem_cache_alloc+0x16f/0x340 mm/slub.c:3867
 kmem_cache_zalloc include/linux/slab.h:701 [inline]
 __kernfs_new_node+0xd8/0x880 fs/kernfs/dir.c:615
 kernfs_new_node+0x13a/0x240 fs/kernfs/dir.c:691
 __kernfs_create_file+0x49/0x2f0 fs/kernfs/file.c:1025
 sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:307
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x4f4/0xf20 fs/sysfs/group.c:152
 internal_create_groups fs/sysfs/group.c:192 [inline]
 sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:218
 create_dir lib/kobject.c:78 [inline]
 kobject_add_internal+0x472/0x8d0 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_init_and_add+0x124/0x190 lib/kobject.c:457
 netdev_queue_add_kobject net/core/net-sysfs.c:1706 [inline]
 netdev_queue_update_kobjects+0x1f3/0x480 net/core/net-sysfs.c:1758
 register_queue_kobjects net/core/net-sysfs.c:1819 [inline]
 netdev_register_kobject+0x265/0x310 net/core/net-sysfs.c:2059
 register_netdevice+0x1191/0x19c0 net/core/dev.c:10261
 register_netdev+0x3b/0x50 net/core/dev.c:10393
 ip6gre_init_net+0x228/0x300 net/ipv6/ip6_gre.c:1621
 ops_init+0x354/0x610 net/core/net_namespace.c:136
 setup_net+0x4d1/0xbc0 net/core/net_namespace.c:339
 copy_net_ns+0x4e3/0x7b0 net/core/net_namespace.c:495
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x122/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x616/0xc00 kernel/fork.c:3428
 __do_sys_unshare kernel/fork.c:3499 [inline]
 __se_sys_unshare kernel/fork.c:3497 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3497
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f398af5f2f7
RSP: 002b:00007fffbca33888 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fffbca338b8 RCX: 00007f398af5f2f7
RDX: 00007f398af5de79 RSI: 00007fffbca33930 RDI: 0000000040000000
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000555556ceb370
R13: 0000000000000003 R14: 0000000000000003 R15: 00007fffbca338f0
 </TASK>
rcu: rcu_preempt kthread starved for 10581 jiffies! g6349 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:24016 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x17d1/0x49f0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 schedule_timeout+0x1bd/0x310 kernel/time/timer.c:2183
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:1663
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862
 kthread+0x2f1/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5119 Comm: syz-executor380 Not tainted 6.8.0-rc6-syzkaller-00011-g45ec2f5f6ed3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:__lock_acquire+0xc6e/0x1fd0 kernel/locking/lockdep.c:5107
Code: 89 d8 48 c1 e8 06 48 8d 3c c5 20 d4 c8 92 be 08 00 00 00 e8 84 6a 84 00 48 bf 00 00 00 00 00 fc ff df 48 0f a3 1d b2 aa 57 11 <0f> 83 f6 08 00 00 49 8d 9d b0 0a 00 00 48 89 d8 48 c1 e8 03 48 89
RSP: 0018:ffffc9000458f990 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 00000000000000ad RCX: ffffffff8171295c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000
RBP: ffff888024e22880 R08: ffffffff92c8d437 R09: 1ffffffff2591a86
R10: dffffc0000000000 R11: fffffbfff2591a87 R12: 0000000000000001
R13: ffff888024e21dc0 R14: 1ffff110049c4514 R15: ffff888024e228a0
FS:  0000555556ceb3c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 0000000024764000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170
 spin_lock_irq include/linux/spinlock.h:376 [inline]
 get_signal+0x246/0x1850 kernel/signal.c:2685
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
 syscall_exit_to_user_mode+0xc8/0x360 kernel/entry/common.c:212
 do_syscall_64+0x108/0x240 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f398af5de79
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbca33888 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f398af5de79
RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000555556ceb370
R13: 0000000000000001 R14: 00007fffbca33900 R15: 00007fffbca338f0
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.496 msecs
sched: RT throttling activated