perf/x86/intel: Fix memory leak on hot-plug allocation fail

We fail to free the shared_regs allocation if the constraint_list
allocation fails.

Cure this and be more consistent in NULL-ing the pointers after free.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 16 insertions, 7 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index b9826a981fb2..6326ae24e4d5 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -2534,7 +2534,7 @@ static int intel_pmu_cpu_prepare(int cpu)
         if (x86_pmu.extra_regs || x86_pmu.lbr_sel_map) {
                 cpuc->shared_regs = allocate_shared_regs(cpu);
                 if (!cpuc->shared_regs)
-                        return NOTIFY_BAD;
+                        goto err;
         }
 
         if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
@@ -2542,18 +2542,27 @@ static int intel_pmu_cpu_prepare(int cpu)
 
                 cpuc->constraint_list = kzalloc(sz, GFP_KERNEL);
                 if (!cpuc->constraint_list)
-                        return NOTIFY_BAD;
+                        goto err_shared_regs;
 
                 cpuc->excl_cntrs = allocate_excl_cntrs(cpu);
-                if (!cpuc->excl_cntrs) {
-                        kfree(cpuc->constraint_list);
-                        kfree(cpuc->shared_regs);
-                        return NOTIFY_BAD;
-                }
+                if (!cpuc->excl_cntrs)
+                        goto err_constraint_list;
+
                 cpuc->excl_thread_id = 0;
         }
 
         return NOTIFY_OK;
+
+err_constraint_list:
+        kfree(cpuc->constraint_list);
+        cpuc->constraint_list = NULL;
+
+err_shared_regs:
+        kfree(cpuc->shared_regs);
+        cpuc->shared_regs = NULL;
+
+err:
+        return NOTIFY_BAD;
 }
 
 static void intel_pmu_cpu_starting(int cpu)