Re: [PATCH] riscv/kprobe: reclaim insn_slot on kprobe unregistration

[liaochang (A)]

在 2022/5/24 23:12, Jisheng Zhang 写道:
> On Mon, May 23, 2022 at 09:51:24AM +0800, Liao Chang wrote:
>> On kprobe registration kernel allocate one insn_slot for new kprobe,
>> but it forget to reclaim the insn_slot on unregistration, leading to a
>> potential leakage.
> 
> + Guo Ren
> 
> Nice catch! I think csky needs the fix as well.
> 
>>
>> This bug reported by Chen Guokai <chenguokai17@xxxxxxxxxxxxxxxx>.
> 
> This needs a "Reported-by: ..." tag

Thanks for comment.

> 
>>
>> Signed-off-by: Liao Chang <liaochang1@xxxxxxxxxx>
>> ---
>>  arch/riscv/kernel/probes/kprobes.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
>> index e6e950b7cf32..f12eb1fbb52c 100644
>> --- a/arch/riscv/kernel/probes/kprobes.c
>> +++ b/arch/riscv/kernel/probes/kprobes.c
>> @@ -110,6 +110,10 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
>>  
>>  void __kprobes arch_remove_kprobe(struct kprobe *p)
>>  {
>> +	if (p->ainsn.api.insn) {
>> +		free_insn_slot(p->ainsn.api.insn, 0);
>> +		p->ainsn.api.insn = NULL;
>> +	}
>>  }
>>  
>>  static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
>> -- 
>> 2.17.1
>>
>>
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> .

-- 
BR,
Liao, Chang