x86/xen: Fix memory leak in xen_smp_intr_init{_pv}()

These local variables @{resched|pmu|callfunc...}_name saves the new
string allocated by kasprintf(), and when bind_{v}ipi_to_irqhandler()
fails, it goes to the @fail tag, and calls xen_smp_intr_free{_pv}() to
free resource, however the new string is not saved, which cause a memory
leak issue. fix it.

Fixes: 9702785a747a ("i386: move xen")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221123155858.11382-2-xiujianfeng@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index c3e1f9a..4b0d6ff 100644 (file)
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -32,30 +32,30 @@ static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
 
 void xen_smp_intr_free(unsigned int cpu)
 {
+       kfree(per_cpu(xen_resched_irq, cpu).name);
+       per_cpu(xen_resched_irq, cpu).name = NULL;
        if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
                unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
                per_cpu(xen_resched_irq, cpu).irq = -1;
-               kfree(per_cpu(xen_resched_irq, cpu).name);
-               per_cpu(xen_resched_irq, cpu).name = NULL;
        }
+       kfree(per_cpu(xen_callfunc_irq, cpu).name);
+       per_cpu(xen_callfunc_irq, cpu).name = NULL;
        if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
                unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
                per_cpu(xen_callfunc_irq, cpu).irq = -1;
-               kfree(per_cpu(xen_callfunc_irq, cpu).name);
-               per_cpu(xen_callfunc_irq, cpu).name = NULL;
        }
+       kfree(per_cpu(xen_debug_irq, cpu).name);
+       per_cpu(xen_debug_irq, cpu).name = NULL;
        if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
                unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
                per_cpu(xen_debug_irq, cpu).irq = -1;
-               kfree(per_cpu(xen_debug_irq, cpu).name);
-               per_cpu(xen_debug_irq, cpu).name = NULL;
        }
+       kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
+       per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
        if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
                unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
                                       NULL);
                per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
-               kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
-               per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
        }
 }
 
@@ -65,6 +65,7 @@ int xen_smp_intr_init(unsigned int cpu)
        char *resched_name, *callfunc_name, *debug_name;
 
        resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
+       per_cpu(xen_resched_irq, cpu).name = resched_name;
        rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
                                    cpu,
                                    xen_reschedule_interrupt,
@@ -74,9 +75,9 @@ int xen_smp_intr_init(unsigned int cpu)
        if (rc < 0)
                goto fail;
        per_cpu(xen_resched_irq, cpu).irq = rc;
-       per_cpu(xen_resched_irq, cpu).name = resched_name;
 
        callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
+       per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
        rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
                                    cpu,
                                    xen_call_function_interrupt,
@@ -86,10 +87,10 @@ int xen_smp_intr_init(unsigned int cpu)
        if (rc < 0)
                goto fail;
        per_cpu(xen_callfunc_irq, cpu).irq = rc;
-       per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 
        if (!xen_fifo_events) {
                debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
+               per_cpu(xen_debug_irq, cpu).name = debug_name;
                rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
                                             xen_debug_interrupt,
                                             IRQF_PERCPU | IRQF_NOBALANCING,
@@ -97,10 +98,10 @@ int xen_smp_intr_init(unsigned int cpu)
                if (rc < 0)
                        goto fail;
                per_cpu(xen_debug_irq, cpu).irq = rc;
-               per_cpu(xen_debug_irq, cpu).name = debug_name;
        }
 
        callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
+       per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
        rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
                                    cpu,
                                    xen_call_function_single_interrupt,
@@ -110,7 +111,6 @@ int xen_smp_intr_init(unsigned int cpu)
        if (rc < 0)
                goto fail;
        per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
-       per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
 
        return 0;
 

diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 480be82..6175f2c 100644 (file)
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -97,18 +97,18 @@ asmlinkage __visible void cpu_bringup_and_idle(void)
 
 void xen_smp_intr_free_pv(unsigned int cpu)
 {
+       kfree(per_cpu(xen_irq_work, cpu).name);
+       per_cpu(xen_irq_work, cpu).name = NULL;
        if (per_cpu(xen_irq_work, cpu).irq >= 0) {
                unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL);
                per_cpu(xen_irq_work, cpu).irq = -1;
-               kfree(per_cpu(xen_irq_work, cpu).name);
-               per_cpu(xen_irq_work, cpu).name = NULL;
        }
 
+       kfree(per_cpu(xen_pmu_irq, cpu).name);
+       per_cpu(xen_pmu_irq, cpu).name = NULL;
        if (per_cpu(xen_pmu_irq, cpu).irq >= 0) {
                unbind_from_irqhandler(per_cpu(xen_pmu_irq, cpu).irq, NULL);
                per_cpu(xen_pmu_irq, cpu).irq = -1;
-               kfree(per_cpu(xen_pmu_irq, cpu).name);
-               per_cpu(xen_pmu_irq, cpu).name = NULL;
        }
 }
 
@@ -118,6 +118,7 @@ int xen_smp_intr_init_pv(unsigned int cpu)
        char *callfunc_name, *pmu_name;
 
        callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
+       per_cpu(xen_irq_work, cpu).name = callfunc_name;
        rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
                                    cpu,
                                    xen_irq_work_interrupt,
@@ -127,10 +128,10 @@ int xen_smp_intr_init_pv(unsigned int cpu)
        if (rc < 0)
                goto fail;
        per_cpu(xen_irq_work, cpu).irq = rc;
-       per_cpu(xen_irq_work, cpu).name = callfunc_name;
 
        if (is_xen_pmu) {
                pmu_name = kasprintf(GFP_KERNEL, "pmu%d", cpu);
+               per_cpu(xen_pmu_irq, cpu).name = pmu_name;
                rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu,
                                             xen_pmu_irq_handler,
                                             IRQF_PERCPU|IRQF_NOBALANCING,
@@ -138,7 +139,6 @@ int xen_smp_intr_init_pv(unsigned int cpu)
                if (rc < 0)
                        goto fail;
                per_cpu(xen_pmu_irq, cpu).irq = rc;
-               per_cpu(xen_pmu_irq, cpu).name = pmu_name;
        }
 
        return 0;