[PATCH] arch: x86: xen: check the return value of kasprintf()

[Jia-Ju Bai <baijiaju1990@xxxxxxxxx>]

The function kasprintf() can fail, but there is no check of its return
value. To fix this bug, its return value should be checked with new
error handling code.

Fixes: f87e4cac4f4e ("xen: SMP guest support")
Fixes: 83b96794e0ea ("x86/xen: split off smp_pv.c")
Fixes: d5de8841355a ("x86: split spinlock implementations out into their own 
files")
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
 arch/x86/xen/smp.c      | 2 ++
 arch/x86/xen/smp_pv.c   | 2 ++
 arch/x86/xen/spinlock.c | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index c3e1f9a7d43a..91261390f8c0 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -65,6 +65,8 @@ int xen_smp_intr_init(unsigned int cpu)
        char *resched_name, *callfunc_name, *debug_name;
 
        resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
+       if (!resched_name)
+               return -ENOMEM;
        rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
                                    cpu,
                                    xen_reschedule_interrupt,
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 4a6019238ee7..7d1471fd1267 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -118,6 +118,8 @@ int xen_smp_intr_init_pv(unsigned int cpu)
        char *callfunc_name, *pmu_name;
 
        callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
+       if (!callfunc_name)
+               return -ENOMEM;
        rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
                                    cpu,
                                    xen_irq_work_interrupt,
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 043c73dfd2c9..ccdb9eddd93b 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -75,6 +75,8 @@ void xen_init_lock_cpu(int cpu)
             cpu, per_cpu(lock_kicker_irq, cpu));
 
        name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
+       if (!name)
+               return;
        irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
                                     cpu,
                                     dummy_handler,
-- 
2.17.1