2019-12-19 22:39:58

by Shakeel Butt

Subject: [PATCH] x86/resctrl: Fix potential memory leak

The set_cache_qos_cfg() is leaking memory when the given level is not
RDT_RESOURCE_L3 or RDT_RESOURCE_L2. Fix that.

Fixes: 99adde9b370de ("x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG")
Signed-off-by: Shakeel Butt <[email protected]>
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 2e3b06d6bbc6..a0c279c7f4b9 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1748,8 +1748,10 @@ static int set_cache_qos_cfg(int level, bool enable)
update = l3_qos_cfg_update;
else if (level == RDT_RESOURCE_L2)
update = l2_qos_cfg_update;
- else
+ else {
+ free_cpumask_var(cpu_mask);
return -EINVAL;
+ }

r_l = &rdt_resources_all[level];
list_for_each_entry(d, &r_l->domains, list) {
--
2.24.1.735.g03f4e72817-goog

2019-12-19 22:52:51

by Fenghua Yu

Subject: Re: [PATCH] x86/resctrl: Fix potential memory leak

On Thu, Dec 19, 2019 at 02:38:34PM -0800, Shakeel Butt wrote:
> The set_cache_qos_cfg() is leaking memory when the given level is not
> RDT_RESOURCE_L3 or RDT_RESOURCE_L2. Fix that.
>
> Fixes: 99adde9b370de ("x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG")
> Signed-off-by: Shakeel Butt <[email protected]>

Acked-by: Fenghua Yu <[email protected]>

Thanks.

-Fenghua

2019-12-19 23:29:08

by Reinette Chatre

Subject: Re: [PATCH] x86/resctrl: Fix potential memory leak

Hi Shakeel,

On 12/19/2019 2:38 PM, Shakeel Butt wrote:
> The set_cache_qos_cfg() is leaking memory when the given level is not
> RDT_RESOURCE_L3 or RDT_RESOURCE_L2. Fix that.

I think it would be valuable to those considering whether they need to
backport to know that RDT_RESOURCE_L3 and RDT_RESOURCE_L2 are currently
the only possible levels with which this function is called. It is thus
not currently possible for this leak to occur. Indeed a valuable safety
to add in case this code may change in the future. Thank you very much.

>
> Fixes: 99adde9b370de ("x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG")
> Signed-off-by: Shakeel Butt <[email protected]>
> ---
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 2e3b06d6bbc6..a0c279c7f4b9 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1748,8 +1748,10 @@ static int set_cache_qos_cfg(int level, bool enable)
> update = l3_qos_cfg_update;
> else if (level == RDT_RESOURCE_L2)
> update = l2_qos_cfg_update;
> - else
> + else {
> + free_cpumask_var(cpu_mask);
> return -EINVAL;
> + }
>
> r_l = &rdt_resources_all[level];
> list_for_each_entry(d, &r_l->domains, list) {
>

Reinette

2019-12-20 01:56:35

by Shakeel Butt

Subject: Re: [PATCH] x86/resctrl: Fix potential memory leak

On Thu, Dec 19, 2019 at 3:27 PM Reinette Chatre
<[email protected]> wrote:
>
> Hi Shakeel,
>
> On 12/19/2019 2:38 PM, Shakeel Butt wrote:
> > The set_cache_qos_cfg() is leaking memory when the given level is not
> > RDT_RESOURCE_L3 or RDT_RESOURCE_L2. Fix that.
>
> I think it would be valuable to those considering whether they need to
> backport to know that RDT_RESOURCE_L3 and RDT_RESOURCE_L2 are currently
> the only possible levels with which this function is called. It is thus
> not currently possible for this leak to occur. Indeed a valuable safety
> to add in case this code may change in the future. Thank you very much.
>

Do you want me to add that info the commit and resend the v2 of the patch?

2019-12-20 05:48:00

by Reinette Chatre

Subject: Re: [PATCH] x86/resctrl: Fix potential memory leak

Hi Shakeel,

On 12/19/2019 5:54 PM, Shakeel Butt wrote:
> On Thu, Dec 19, 2019 at 3:27 PM Reinette Chatre
> <[email protected]> wrote:
>> On 12/19/2019 2:38 PM, Shakeel Butt wrote:
>>> The set_cache_qos_cfg() is leaking memory when the given level is not
>>> RDT_RESOURCE_L3 or RDT_RESOURCE_L2. Fix that.
>>
>> I think it would be valuable to those considering whether they need to
>> backport to know that RDT_RESOURCE_L3 and RDT_RESOURCE_L2 are currently
>> the only possible levels with which this function is called. It is thus
>> not currently possible for this leak to occur. Indeed a valuable safety
>> to add in case this code may change in the future. Thank you very much.
>>
>
> Do you want me to add that info the commit and resend the v2 of the patch?
>

Yes please.

Thank you very much

Reinette