syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9274/1:b..l
	(detected by 1, t=10503 jiffies, g=42489, q=206 ncpus=2)
task:modprobe        state:R  running task     stack:24352 pid:9274  ppid:4420   flags:0x00004000
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:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_is_held_type+0x64/0x190 kernel/locking/lockdep.c:5701
Code: 00 00 00 65 48 8b 1d 9b 9a ea 75 83 bb dc 0a 00 00 00 0f 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 24 <4c> 8b 2c 24 fa 48 c7 c7 60 12 8c 8a e8 eb 12 00 00 65 ff 05 a4 a4
RSP: 0018:ffffc900035df418 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88802b5cbb80 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff88802c1b5b58
RBP: 00000000ffffffff R08: ffff88802b5cbb80 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802419de80 R14: ffff88802c1b5b58 R15: 00000000ffffffff
 lock_is_held include/linux/lockdep.h:283 [inline]
 mt_locked lib/maple_tree.c:-1 [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+0x43ce/0x4c90 lib/maple_tree.c:7247
 validate_mm_mt+0xcd/0x420 mm/mmap.c:295
 __split_vma+0x30/0x500 mm/mmap.c:2355
 do_mas_align_munmap+0x351/0x1220 mm/mmap.c:2480
 do_mas_munmap+0x240/0x2b0 mm/mmap.c:2650
 __mmap_region mm/mmap.c:2698 [inline]
 mmap_region+0x6e5/0x1c70 mm/mmap.c:2916
 do_mmap+0x958/0xfd0 mm/mmap.c:1436
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
 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: 0033:0x7f68cde64242
RSP: 002b:00007ffc1a637b08 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f68cdb88000 RCX: 00007f68cde64242
RDX: 0000000000000005 RSI: 0000000000002000 RDI: 00007f68cdb88000
RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000002000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc1a637b58
R13: 00007f68cde41050 R14: 00007ffc1a637f40 R15: 00000fff834c6f64
 </TASK>
rcu: rcu_preempt kthread starved for 10533 jiffies! g42489 f0x0 RCU_GP_WAIT_FQS(5) ->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: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
 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
 rcu_gp_fqs_loop+0x30b/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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9279 Comm: syz.7.1036 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc900036bfcf8 EFLAGS: 00010202
RAX: 00007f4bb4486400 RBX: ffffc900036bfd60 RCX: 0000000000000080
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffc900036bfde0
RBP: ffffc900036bff10 R08: dffffc0000000000 R09: ffffc900036bfd60
R10: 0000000000000000 R11: 0000000000000018 R12: ffff8880306fbb80
R13: 1ffff920006d7ffe R14: 1ffff920006d7fa8 R15: ffffc900036bfff0
FS:  00007f4bb44876c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c442701 CR3: 000000006aafd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 restore_sigcontext arch/x86/kernel/signal.c:87 [inline]
 __ia32_sys_rt_sigreturn+0x1a6/0x790 arch/x86/kernel/signal.c:675
 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: 0033:0x7f4bb352b829
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:00007f4bb44864c0 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f4bb37e6360 RCX: 00007f4bb352b829
RDX: 00007f4bb44864c0 RSI: 00007f4bb44865f0 RDI: 0000000000000021
RBP: 00007f4bb3613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f4bb37e63f8 R14: 00007f4bb37e6360 R15: 00007ffc0f846a18
 </TASK>