[patch RFC 01/38] iommu/amd: Prevent NULL pointer dereference

Thomas Gleixner
2020-08-21T02:19:49Z

[-- Attachment #1: iommu-amd--Prevent-NULL-pointer-dereference.patch --]
[-- Type: text/plain, Size: 672 bytes --]

Dereferencing irq_data before checking it for NULL is suboptimal.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
---
drivers/iommu/amd/iommu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3717,8 +3717,8 @@ static int irq_remapping_alloc(struct ir

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;
}