syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7892/1:b..l P3637/1:b..l
	(detected by 0, t=10503 jiffies, g=37441, q=140 ncpus=2)
task:udevd           state:R  running task     stack:23040 pid:3637  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xf6/0x100 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x11b/0x180 kernel/sched/wait.c:208
 sock_def_readable+0x15b/0x280 net/core/sock.c:3313
 __netlink_sendskb net/netlink/af_netlink.c:1264 [inline]
 netlink_sendskb+0x97/0x130 net/netlink/af_netlink.c:1270
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f62cd4a7407
RSP: 002b:00007ffcc60ce310 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f62cdb4a880 RCX: 00007f62cd4a7407
RDX: 0000000000000000 RSI: 00007ffcc60ce370 RDI: 0000000000000004
RBP: 000055b372f4e0b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b4
R13: 000055b372f219e0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:rm              state:R  running task     stack:23968 pid:7892  ppid:7808   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:mas_slot lib/maple_tree.c:-1 [inline]
RIP: 0010:mas_validate_limits lib/maple_tree.c:7154 [inline]
RIP: 0010:mt_validate+0x218d/0x4c90 lib/maple_tree.c:7242
Code: 75 7b f7 41 8d 5d 01 89 df 4c 8b 74 24 30 44 89 f6 e8 b7 76 7b f7 44 39 f3 0f 8d 0a 05 00 00 4c 89 e1 4c 8b a4 24 20 01 00 00 <48> 89 5c 24 20 0f b6 c3 48 8b 54 24 48 4c 8d 34 c2 4c 89 f0 48 c1
RSP: 0018:ffffc9000cf6f8a0 EFLAGS: 00000283
RAX: ffffffff8a055989 RBX: 000000000000000e RCX: dffffc0000000000
RDX: ffff888054f35940 RSI: 0000000000000010 RDI: 000000000000000e
RBP: ffffc9000cf6fa70 R08: ffff888054f35940 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff88807ec41e00
R13: 000000000000000d R14: 0000000000000010 R15: 000000000000000f
 validate_mm_mt+0xcd/0x420 mm/mmap.c:295
 __split_vma+0x30/0x500 mm/mmap.c:2355
 mprotect_fixup+0x597/0x7f0 mm/mprotect.c:623
 do_mprotect_pkey+0x754/0xa40 mm/mprotect.c:792
 __do_sys_mprotect mm/mprotect.c:819 [inline]
 __se_sys_mprotect mm/mprotect.c:816 [inline]
 __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:816
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdb3e7ce2c7
RSP: 002b:00007ffc84cda128 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007fdb3e7ab050 RCX: 00007fdb3e7ce2c7
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007fdb3e4f5000
RBP: 00007ffc84cda3f0 R08: 0000000000000000 R09: 00007fdb3e547870
R10: 00007fdb3e7ab050 R11: 0000000000000206 R12: 0000000000000010
R13: 000000b902e0653f R14: 0000000000000000 R15: 00007fdb3e7e2310
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10564 jiffies! g37441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=18458
rcu: rcu_preempt kthread starved for 10567 jiffies! g37441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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: 7874 Comm: syz.7.883 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:tick_nohz_user_enter_prepare include/linux/tick.h:320 [inline]
RIP: 0010:exit_to_user_mode_loop+0x19/0x110 kernel/entry/common.c:190
Code: eb aa 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 56 53 50 49 89 f6 41 f7 c6 0e 30 02 00 0f 84 e6 00 00 00 48 89 fb eb 1d <e8> c2 dc a9 08 65 48 8b 05 5a 95 94 7e 4c 8b 30 41 f7 c6 0e 30 02
RSP: 0018:ffffc9000c8d7ed0 EFLAGS: 00000046
RAX: 0000000080000000 RBX: ffffc9000c8d7f58 RCX: b8d70f3954e6c900
RDX: ffffc90004a21000 RSI: 0000000000000000 RDI: ffffffff816dda9c
RBP: ffffc9000c8d7f48 R08: dffffc0000000000 R09: ffffed100e3e46f1
R10: ffffed100e3e46f1 R11: 1ffff1100e3e46f0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000004 R15: ffff88807cf88000
FS:  00007fd4929496c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb3e613a90 CR3: 000000007e326000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 exit_to_user_mode_prepare+0xee/0x180 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: 0033:0x7fd491bb7700
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d ea 3b 08 00 e8 f5 8e f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007fd492948a78 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fd491de5fa0 RCX: 00007fd491b8efc9
RDX: 00007fd492948a80 RSI: 00007fd492948bb0 RDI: 0000000000000021
RBP: 00007fd491c11f91 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd491de6038 R14: 00007fd491de5fa0 R15: 00007ffd9ea4bad8
 </TASK>