rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P14516/1:b..l
rcu: 	(detected by 1, t=10505 jiffies, g=151069, q=286 ncpus=2)
task:syz-executor    state:R  running task     stack:22320 pid:14516 tgid:14516 ppid:14515  task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 preempt_schedule_common+0x7f/0xd0
 preempt_schedule_thunk+0x16/0x40
 _raw_spin_unlock+0x41/0x50
 copy_pmd_range+0x5176/0x5c10
 copy_page_range+0xc82/0x1290
 dup_mmap+0xf17/0x1dc0
 copy_mm+0x11a/0x480
 copy_process+0x1e75/0x43e0
 kernel_clone+0x2d7/0x940
 __x64_sys_clone+0x1b6/0x230
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08ddbc6bd2
RSP: 002b:00007ffe5eae3fc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe5eae3fc0 RCX: 00007f08ddbc6bd2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe5eae414c R08: 0000000000000000 R09: 0000000000000001
R10: 0000555556d977d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000b5577 R15: 00007ffe5eae41a0
 </TASK>
rcu: rcu_preempt kthread starved for 10482 jiffies! g151069 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27696 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 27487 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:smp_call_function_many_cond+0x61e/0x1500
Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 51 54 0c 00 41 83 e7 01 75 07 e8 46 4f 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01
RSP: 0018:ffffc90007fef420 EFLAGS: 00000293
RAX: ffffffff81bb697e RBX: ffff888121043948 RCX: ffff88816ab91e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90007fef570 R08: ffff88816ab9339f R09: 1ffff1102d572673
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff11024208729
R13: 0000000000000000 R14: ffff888121043940 R15: 0000000000000001
FS:  000055556bc1f500(0000) GS:ffff8882a8cd6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5a991556c8 CR3: 00000001a1cd2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 flush_tlb_mm_range+0x8ff/0x1090
 dup_mmap+0x1758/0x1dc0
 copy_mm+0x11a/0x480
 copy_process+0x1e75/0x43e0
 kernel_clone+0x2d7/0x940
 __x64_sys_clone+0x1b6/0x230
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f865ddc6bd2
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007fff321a3650 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fff321a3650 RCX: 00007f865ddc6bd2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fff321a37dc R08: 0000000000000000 R09: 0000000000000001
R10: 000055556bc1f7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000b5619 R15: 00007fff321a3830
 </TASK>
