2022-05-25 18:40:25

by Guo Ren

Subject: Re: [PATCH v2] riscv/kprobe: reclaim insn_slot on kprobe unregistration

On Wed, May 25, 2022 at 9:46 AM Liao Chang <[email protected]> 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.
>
> Reported-by: Chen Guokai <[email protected]>
> Signed-off-by: Liao Chang <[email protected]>
> ---
> v2:
> Add Reported-by tag
>
> 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;
> + }
Thx reviewed-by: Guo Ren <[email protected]>

You also could give a fixup patch to csky, thx:

diff --git a/arch/csky/kernel/probes/kprobes.c
b/arch/csky/kernel/probes/kprobes.c
index 42920f25e73c..661da54b418f 100644
--- a/arch/csky/kernel/probes/kprobes.c
+++ b/arch/csky/kernel/probes/kprobes.c
@@ -124,6 +124,10 @@ 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)

> }
>
> static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
> --
> 2.17.1
>


--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/

2022-05-25 19:52:52

by Liao, Chang

Subject: Re: [PATCH v2] riscv/kprobe: reclaim insn_slot on kprobe unregistration

在 2022/5/25 14:23, Guo Ren 写道:
> On Wed, May 25, 2022 at 9:46 AM Liao Chang <[email protected]> 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.
>>
>> Reported-by: Chen Guokai <[email protected]>
>> Signed-off-by: Liao Chang <[email protected]>
>> ---
>> v2:
>> Add Reported-by tag
>>
>> 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;
>> + }
> Thx reviewed-by: Guo Ren <[email protected]>
>
> You also could give a fixup patch to csky, thx:
>
> diff --git a/arch/csky/kernel/probes/kprobes.c
> b/arch/csky/kernel/probes/kprobes.c
> index 42920f25e73c..661da54b418f 100644
> --- a/arch/csky/kernel/probes/kprobes.c
> +++ b/arch/csky/kernel/probes/kprobes.c
> @@ -124,6 +124,10 @@ 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;
> + }
> }

Sure, I will, thanks.
>
> static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
>
>> }
>>
>> static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
>> --
>> 2.17.1
>>
>
>

--
BR,
Liao, Chang

2022-05-26 12:43:19

by Jisheng Zhang

Subject: Re: [PATCH v2] riscv/kprobe: reclaim insn_slot on kprobe unregistration

On Wed, May 25, 2022 at 02:23:50PM +0800, Guo Ren wrote:
> On Wed, May 25, 2022 at 9:46 AM Liao Chang <[email protected]> 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.
> >
> > Reported-by: Chen Guokai <[email protected]>
> > Signed-off-by: Liao Chang <[email protected]>

Reviewed-by: Jisheng Zhang <[email protected]>
> > ---
> > v2:
> > Add Reported-by tag
> >
> > 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;
> > + }
> Thx reviewed-by: Guo Ren <[email protected]>
>
> You also could give a fixup patch to csky, thx:
>
> diff --git a/arch/csky/kernel/probes/kprobes.c
> b/arch/csky/kernel/probes/kprobes.c
> index 42920f25e73c..661da54b418f 100644
> --- a/arch/csky/kernel/probes/kprobes.c
> +++ b/arch/csky/kernel/probes/kprobes.c
> @@ -124,6 +124,10 @@ 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)
>
> > }
> >
> > static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
> > --
> > 2.17.1
> >
>
>
> --
> Best Regards
> Guo Ren
>
> ML: https://lore.kernel.org/linux-csky/