From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 26 Aug 2020 11:16:29 +0000 (+0200)
Subject: iommu/amd: Prevent NULL pointer dereference
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=23357b61f8062a8a8c9c84c0252056cd6d849ec8;p=linux.git

iommu/amd: Prevent NULL pointer dereference

Dereferencing irq_data before checking it for NULL is suboptimal.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 07ae8b93887e5..db44ce67b979b 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3731,8 +3731,8 @@ static int irq_remapping_alloc(struct irq_domain *domain, unsigned int virq,
 
 	for (i = 0; i < nr_irqs; i++) {
 		irq_data = irq_domain_get_irq_data(domain, virq + i);
-		cfg = irqd_cfg(irq_data);
-		if (!irq_data || !cfg) {
+		cfg = irq_data ? irqd_cfg(irq_data) : NULL;
+		if (!cfg) {
 			ret = -EINVAL;
 			goto out_free_data;
 		}