rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4633/1:b..l
	(detected by 0, t=10502 jiffies, g=11789, q=482 ncpus=2)
task:udevd           state:R  running task     stack:23648 pid:4633  ppid:3637   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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 2e 0f 1f 84 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 80 96 9e 0c 48 89 de 5b e9 f7 65 4f 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d d4 98 81 7e 65 8b 15 d5 98 81 7e 81 e2 00
RSP: 0018:ffffc900052ff4f8 EFLAGS: 00000246
RAX: ffffffff8a05ab8f RBX: 0000000000000006 RCX: 0000000000000000
RDX: ffff88807a59d940 RSI: 0000000000000300 RDI: 0000000000000300
RBP: ffffc900052ff6d0 R08: ffff88807a59d940 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff8880673e6798
R13: ffff888063b7be80 R14: ffff88807df95a00 R15: 0000000000000300
 mt_locked lib/maple_tree.c:807 [inline]
 mt_slot lib/maple_tree.c:814 [inline]
 mas_slot lib/maple_tree.c:847 [inline]
 mt_validate_nulls lib/maple_tree.c:7191 [inline]
 mt_validate+0x438d/0x4c90 lib/maple_tree.c:7247
 validate_mm_mt+0xcd/0x420 mm/mmap.c:295
 validate_mm+0xcc/0x2b0 mm/mmap.c:332
 __vma_adjust+0x17e0/0x1c60 mm/mmap.c:879
 vma_adjust include/linux/mm.h:2810 [inline]
 __split_vma+0x3a7/0x500 mm/mmap.c:-1
 do_mas_align_munmap+0x351/0x1220 mm/mmap.c:2480
 do_mas_munmap+0x240/0x2b0 mm/mmap.c:2650
 __vm_munmap+0x18d/0x290 mm/mmap.c:2936
 __do_sys_munmap mm/mmap.c:2961 [inline]
 __se_sys_munmap mm/mmap.c:2958 [inline]
 __x64_sys_munmap+0x5c/0x70 mm/mmap.c:2958
 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: 0033:0x7f187ec53097
RSP: 002b:00007ffff9b7e548 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00005573ac3d94f0 RCX: 00007f187ec53097
RDX: 00005573ac3c5ee8 RSI: 0000000000000200 RDI: 00007f187eb47000
RBP: 0000000000000009 R08: 00005573ac3bcee0 R09: 0000000000000003
R10: 0000000000000040 R11: 0000000000000246 R12: 00005573ac3bd0b0
R13: 00007f187edf539c R14: 0000000000001200 R15: 0000000000000009
 </TASK>
rcu: rcu_preempt kthread starved for 10532 jiffies! g11789 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:26880 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:2167
 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: 4952 Comm: syz.4.65 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:recalc_sigpending+0x0/0x1c0 kernel/signal.c:183
Code: f1 80 e1 07 fe c1 38 c1 0f 8c be fe ff ff 4c 89 f7 e8 e4 e4 80 00 e9 b1 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <55> 41 57 41 56 41 55 41 54 53 49 bc 00 00 00 00 00 fc ff df e8 d7
RSP: 0018:ffffc90003847b48 EFLAGS: 00000016
RAX: ffffffff815039d4 RBX: ffffc90003847e00 RCX: 0000000000000002
RDX: ffff888024afd940 RSI: 0000000000000011 RDI: 000000000000000e
RBP: ffff888024afe250 R08: ffff88823b400000 R09: 0000000000000001
R10: 00000000686737ad R11: 1ffffffff1c3ed55 R12: 1ffff1100495fc4a
R13: ffff888024afe260 R14: ffff888024afd940 R15: 0000000000000011
FS:  00007fbec4abd6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffa0ac8910 CR3: 0000000072459000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dequeue_signal+0x103/0x4b0 kernel/signal.c:676
 get_signal+0x547/0x1350 kernel/signal.c:2751
 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 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: 0033:0x7fbec3b8efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbec4abd0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007fbec3de5fa8 RCX: 00007fbec3b8efc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbec3de5fa8
RBP: 00007fbec3de5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbec3de6038 R14: 00007ffe6f839da0 R15: 00007ffe6f839e88
 </TASK>