[PATCH v2 0/2]x86/xen: Fix memory leak issue

[PATCH v2 0/2]x86/xen: Fix memory leak issue

[Xiu Jianfeng]

The new string allocated by kasprintf() is leaked on error paths

v2: follow Juergen's suggestion.

Xiu Jianfeng (2):
  x86/xen: Fix memory leak in xen_smp_intr_init{_pv}()
  x86/xen: Fix memory leak in xen_init_lock_cpu()

 arch/x86/xen/smp.c      | 24 ++++++++++++------------
 arch/x86/xen/smp_pv.c   | 12 ++++++------
 arch/x86/xen/spinlock.c |  6 +++---
 3 files changed, 21 insertions(+), 21 deletions(-)

-- 
2.17.1

[PATCH v2 1/2] x86/xen: Fix memory leak in xen_smp_intr_init{_pv}()

[Xiu Jianfeng]

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>
---
 arch/x86/xen/smp.c    | 24 ++++++++++++------------
 arch/x86/xen/smp_pv.c | 12 ++++++------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index c3e1f9a7d43a..4b0d6fff88de 100644
--- 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 480be82e9b7b..6175f2c5c822 100644
--- 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;
-- 
2.17.1

[PATCH v2 2/2] x86/xen: Fix memory leak in xen_init_lock_cpu()

[Xiu Jianfeng]

In xen_init_lock_cpu(), the @name has allocated new string by kasprintf(),
if bind_ipi_to_irqhandler() fails, it should be freed, otherwise may lead
to a memory leak issue, fix it.

Fixes: 2d9e1e2f58b5 ("xen: implement Xen-specific spinlocks")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
---
 arch/x86/xen/spinlock.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 043c73dfd2c9..5c6fc16e4b92 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -75,6 +75,7 @@ void xen_init_lock_cpu(int cpu)
 	     cpu, per_cpu(lock_kicker_irq, cpu));
 
 	name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
+	per_cpu(irq_name, cpu) = name;
 	irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
 				     cpu,
 				     dummy_handler,
@@ -85,7 +86,6 @@ void xen_init_lock_cpu(int cpu)
 	if (irq >= 0) {
 		disable_irq(irq); /* make sure it's never delivered */
 		per_cpu(lock_kicker_irq, cpu) = irq;
-		per_cpu(irq_name, cpu) = name;
 	}
 
 	printk("cpu %d spinlock event irq %d\n", cpu, irq);
@@ -98,6 +98,8 @@ void xen_uninit_lock_cpu(int cpu)
 	if (!xen_pvspin)
 		return;
 
+	kfree(per_cpu(irq_name, cpu));
+	per_cpu(irq_name, cpu) = NULL;
 	/*
 	 * When booting the kernel with 'mitigations=auto,nosmt', the secondary
 	 * CPUs are not activated, and lock_kicker_irq is not initialized.
@@ -108,8 +110,6 @@ void xen_uninit_lock_cpu(int cpu)
 
 	unbind_from_irqhandler(irq, NULL);
 	per_cpu(lock_kicker_irq, cpu) = -1;
-	kfree(per_cpu(irq_name, cpu));
-	per_cpu(irq_name, cpu) = NULL;
 }
 
 PV_CALLEE_SAVE_REGS_THUNK(xen_vcpu_stolen);
-- 
2.17.1

Re: [PATCH v2 1/2] x86/xen: Fix memory leak in xen_smp_intr_init{_pv}()

[Juergen Gross]

[-- Attachment #1.1.1: Type: text/plain, Size: 522 bytes --]

On 23.11.22 16:58, Xiu Jianfeng wrote:
> 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>


Juergen


[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 3149 bytes --]

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]

Re: [PATCH v2 2/2] x86/xen: Fix memory leak in xen_init_lock_cpu()

[Juergen Gross]

[-- Attachment #1.1.1: Type: text/plain, Size: 418 bytes --]

On 23.11.22 16:58, Xiu Jianfeng wrote:
> In xen_init_lock_cpu(), the @name has allocated new string by kasprintf(),
> if bind_ipi_to_irqhandler() fails, it should be freed, otherwise may lead
> to a memory leak issue, fix it.
> 
> Fixes: 2d9e1e2f58b5 ("xen: implement Xen-specific spinlocks")
> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen


[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 3149 bytes --]

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]