syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4391/1:b..l
	(detected by 0, t=10503 jiffies, g=43845, q=99 ncpus=2)
task:udevd           state:R  running task     stack:22080 pid:4391  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:debug_lockdep_rcu_enabled+0x9/0x30 kernel/rcu/update.c:280
Code: 20 04 8c 8a 48 c7 c6 00 28 8c 8a e8 71 23 35 f7 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 31 c0 83 3d e7 93 07 04 00 <74> 1d 83 3d 72 c7 07 04 00 74 14 65 48 8b 0d 44 97 ea 75 31 c0 83
RSP: 0018:ffffc900046f74f8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 000000000000000b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 000000000000000e RDI: 000000000000000b
RBP: ffffc900046f76d0 R08: ffff88807b4a5940 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff8880265b85e8
R13: ffff88807285be80 R14: ffff888028616180 R15: ffff88807285bee0
 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+0x4335/0x4c90 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: 0033:0x7ff38f852097
RSP: 002b:00007fff38680a48 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00005571f7f89c30 RCX: 00007ff38f852097
RDX: 00005571f7f19828 RSI: 0000000000000200 RDI: 00007ff38f15b000
RBP: 000000000000000f R08: 00005571f7f89c00 R09: 0000000000000003
R10: 0000000000000040 R11: 0000000000000246 R12: 00005571f7f1b1f0
R13: 00007ff38f9f439c R14: 0000000000001e00 R15: 0000000000000009
 </TASK>
rcu: rcu_preempt kthread starved for 10524 jiffies! g43845 f0x0 RCU_GP_DOING_FQS(6) ->state=0x0 ->cpu=0
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
 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
 force_qs_rnp kernel/rcu/tree.c:-1 [inline]
 rcu_gp_fqs kernel/rcu/tree.c:-1 [inline]
 rcu_gp_fqs_loop+0x6a1/0x1310 kernel/rcu/tree.c:1728
 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:
CPU: 0 PID: 8773 Comm: syz.2.925 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline]
RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 1f ea f7 02 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90004e97cb0 EFLAGS: 00000246
RAX: 00000000000000f6 RBX: ffffffff8c5e4b88 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff520009d2f85
R10: fffff520009d2f85 R11: 1ffff920009d2f84 R12: ffff8880b8e33e01
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020
FS:  0000555571113500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0d8d3ed000 CR3: 000000005fa0a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31
 irq_work_queue+0x95/0x140 kernel/irq_work.c:114
 bpf_send_signal_common+0x2b2/0x420 kernel/trace/bpf_trace.c:879
 ____bpf_send_signal kernel/trace/bpf_trace.c:888 [inline]
 bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:886
 bpf_prog_7ba5217f62dcd359+0x38/0x3c
 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18
 trace_sys_enter+0x6b/0x80 include/trace/events/syscalls.h:18
 syscall_trace_enter+0xf0/0x150 kernel/entry/common.c:81
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:77
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa4b652b829
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007ffe7918c180 EFLAGS: 00000246 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007fa4b67e6098 RCX: 00007fa4b652b829
RDX: 00007ffe7918c180 RSI: 00007ffe7918c2b0 RDI: 0000000000000011
RBP: 0000000000000001 R08: 0000000000000006 R09: 000000137918ca1f
R10: 00007fa4b67e5fa0 R11: 0000000000000246 R12: 00007fa4b67e609c
R13: 00007fa4b67e6090 R14: 00000000000010a7 R15: 0000000000000005
 </TASK>