kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401161119.iof6BQsf-lkp@intel.com/

---
v2: Initial rc and return errno in error paths
---
 arch/x86/xen/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 4b0d6fff88de..0ea4f1b2ab21 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -61,10 +61,14 @@ void xen_smp_intr_free(unsigned int cpu)
 
 int xen_smp_intr_init(unsigned int cpu)
 {
-	int rc;
+	int rc = 0;
 	char *resched_name, *callfunc_name, *debug_name;
 
 	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
+	if (!resched_name) {
+		rc = -ENOMEM;
+		goto fail;
+	}
 	per_cpu(xen_resched_irq, cpu).name = resched_name;
 	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
 				    cpu,
@@ -77,6 +81,10 @@ int xen_smp_intr_init(unsigned int cpu)
 	per_cpu(xen_resched_irq, cpu).irq = rc;
 
 	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
+	if (!callfunc_name) {
+		rc = -ENOMEM;
+		goto fail;
+	}
 	per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
 				    cpu,
@@ -90,6 +98,10 @@ int xen_smp_intr_init(unsigned int cpu)
 
 	if (!xen_fifo_events) {
 		debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
+		if (!debug_name) {
+			rc = -ENOMEM;
+			goto fail;
+		}
 		per_cpu(xen_debug_irq, cpu).name = debug_name;
 		rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
 					     xen_debug_interrupt,
@@ -101,6 +113,10 @@ int xen_smp_intr_init(unsigned int cpu)
 	}
 
 	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
+	if (!callfunc_name) {
+		rc = -ENOMEM;
+		goto fail;
+	}
 	per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
 	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
 				    cpu,
-- 
2.39.2

> kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure. Ensure the allocation was successful
> by checking the pointer validity.
…
> +++ b/arch/x86/xen/smp.c
> @@ -61,10 +61,14 @@ void xen_smp_intr_free(unsigned int cpu)
>
>  int xen_smp_intr_init(unsigned int cpu)
>  {
> -	int rc;
> +	int rc = 0;

I find the indication of a successful function execution sufficient by
the statement “return 0;” at the end.
How do you think about to omit such an extra variable initialisation?


>  	char *resched_name, *callfunc_name, *debug_name;
>
>  	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
> +	if (!resched_name) {
> +		rc = -ENOMEM;
> +		goto fail;
> +	}
>  	per_cpu(xen_resched_irq, cpu).name = resched_name;
>  	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
>  				    cpu,

You propose to apply the same error code in four if branches.
I suggest to avoid the specification of duplicate assignment statements
for this purpose.
How do you think about to use another label like “e_nomem”?

Regards,
Markus