[PATCH 4.19 037/103] x86/resctrl: Fix potential memory leak

Greg Kroah-Hartman
2020-01-22T09:48:12Z

From: Shakeel Butt <shakeelb@google.com>

commit ab6a2114433a3b5b555983dcb9b752a85255f04b upstream.

set_cache_qos_cfg() is leaking memory when the given level is not
RDT_RESOURCE_L3 or RDT_RESOURCE_L2. At the moment, this function is
called with only valid levels but move the allocation after the valid
level checks in order to make it more robust and future proof.

[ bp: Massage commit message. ]

Fixes: 99adde9b370de ("x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20200102165844.133133-1-shakeelb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1749,9 +1749,6 @@ static int set_cache_qos_cfg(int level,
struct rdt_domain *d;
int cpu;

- if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
- return -ENOMEM;
-
if (level == RDT_RESOURCE_L3)
update = l3_qos_cfg_update;
else if (level == RDT_RESOURCE_L2)
@@ -1759,6 +1756,9 @@ static int set_cache_qos_cfg(int level,
else
return -EINVAL;

+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
r_l = &rdt_resources_all[level];
list_for_each_entry(d, &r_l->domains, list) {
/* Pick one CPU from each domain instance to update MSR */