syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P17292/1:b..l P17320/1:b..l
	(detected by 1, t=10502 jiffies, g=148429, q=281 ncpus=2)
task:modprobe        state:R  running task     stack:24352 pid:17320 ppid:5120   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 include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xe27/0x10d0 mm/filemap.c:3499
 do_fault_around mm/memory.c:4600 [inline]
 do_read_fault mm/memory.c:4626 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x2889/0x3e70 mm/memory.c:5294
 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f320c0ecd90
RSP: 002b:00007ffd47e669f8 EFLAGS: 00010206
RAX: 00007f320c169e38 RBX: 00007ffd47e66a98 RCX: 00007f320c161960
RDX: 00007ffd47e66ac0 RSI: 000000000000002f RDI: 00007ffd47e67f96
RBP: 00007ffd47e67f96 R08: 00007f320c268af8 R09: 0000000000000000
R10: 00007ffd47e666c0 R11: 0000000000000246 R12: 00007ffd47e66a98
R13: 00007ffd47e66ac0 R14: 00007f320c15ec40 R15: 0000000000000000
 </TASK>
task:syz.0.3841      state:R  running task     stack:25824 pid:17292 ppid:14325  flags:0x00004004
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:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0x66/0xe0 kernel/kcov.c:349
Code: 17 90 8a 48 8b 54 24 20 65 4c 8b 05 74 9a 81 7e 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d 62 9a 81 7e <41> 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 00 00 75 d9 41 83 b8 1c
RSP: 0018:ffffc90014a6f460 EFLAGS: 00000202
RAX: 0000000000000003 RBX: ffff88802aa6e21c RCX: 0000000000000005
RDX: ffffffff8a045cce RSI: ffffffff8e0853f0 RDI: 0000000000000003
RBP: ffffc90014a6f650 R08: ffff888076a4d940 R09: 0000000000000002
R10: 0000000000000003 R11: 0000000080000000 R12: dffffc0000000000
R13: ffff88802aa6e21c R14: 0000000000000003 R15: ffff88802aa6e200
 ma_pivots lib/maple_tree.c:630 [inline]
 mtree_range_walk+0xee/0x7b0 lib/maple_tree.c:2962
 mas_state_walk lib/maple_tree.c:3901 [inline]
 mt_find+0x230/0x810 lib/maple_tree.c:6537
 find_vma+0x126/0x1a0 mm/mmap.c:1898
 lock_mm_and_find_vma+0x71/0x2f0 mm/memory.c:5387
 do_user_addr_fault+0x2db/0xb10 arch/x86/mm/fault.c:1312
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:__put_user_nocheck_4+0x3/0x11
Code: 00 00 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 48 bb f9 ef ff ff ff 7f
RSP: 0018:ffffc90014a6f8d8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000038b030
RDX: ffff888076a4d940 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90014a6fa70 R08: dffffc0000000000 R09: fffff5200294ded9
R10: fffff5200294ded9 R11: 1ffff9200294ded8 R12: dffffc0000000000
R13: 000020000038b000 R14: 0000000000000000 R15: 0000000000000002
 ____sys_recvmsg+0x367/0x580 net/socket.c:2751
 ___sys_recvmsg+0x1b2/0x510 net/socket.c:2780
 do_recvmmsg+0x359/0x7d0 net/socket.c:2874
 __sys_recvmmsg net/socket.c:2953 [inline]
 __do_sys_recvmmsg net/socket.c:2976 [inline]
 __se_sys_recvmmsg net/socket.c:2969 [inline]
 __x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2969
 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: 0033:0x7f58f698ebe9
RSP: 002b:00007f58f7768038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f58f6bc6090 RCX: 00007f58f698ebe9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f58f6a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f58f6bc6128 R14: 00007f58f6bc6090 R15: 00007ffd94b8a8c8
 </TASK>
rcu: rcu_preempt kthread starved for 10542 jiffies! g148429 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:27432 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:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 37 b2 af f7 e9 4c ff ff ff e8 fd 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 87 63 65 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6
RAX: 70c6803aa9154c00 RBX: ffffffff8a213f27 RCX: 70c6803aa9154c00
RDX: 0000000000000001 RSI: ffffffff8a8c0300 RDI: ffffffff8adefae0
RBP: ffffc90000177f20 R08: dffffc0000000000 R09: ffffed10171e6af6
R10: ffffed10171e6af6 R11: 1ffff110171e6af5 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff888017739dc0 R15: 1ffffffff1c3ee66
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c356003 CR3: 000000005fabe000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1fc/0x570 kernel/sched/idle.c:303
 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>