From 87f2d1c662fa1761359fdf558246f97e484d177a Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Fri, 6 Mar 2020 18:47:20 +0100 Subject: [PATCH] genirq/irqdomain: Check pointer in irq_domain_alloc_irqs_hierarchy() irq_domain_alloc_irqs_hierarchy() has 3 call sites in the compilation unit but only one of them checks for the pointer which is being dereferenced inside the called function. Move the check into the function. This allows for catching the error instead of the following crash: Unable to handle kernel NULL pointer dereference at virtual address 00000000 PC is at 0x0 LR is at gpiochip_hierarchy_irq_domain_alloc+0x11f/0x140 ... [] (gpiochip_hierarchy_irq_domain_alloc) [] (__irq_domain_alloc_irqs) [] (irq_create_fwspec_mapping) [] (gpiochip_to_irq) [] (gpiod_to_irq) [] (gpio_irqs_init [gpio_irqs]) [] (gpio_irqs_exit+0xecc/0xe84 [gpio_irqs]) Code: bad PC value Signed-off-by: Alexander Sverdlin Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200306174720.82604-1-alexander.sverdlin@nokia.com --- kernel/irq/irqdomain.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index fdfc2132d2a9..35b8d97c3a1d 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1310,6 +1310,11 @@ int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain, unsigned int irq_base, unsigned int nr_irqs, void *arg) { + if (!domain->ops->alloc) { + pr_debug("domain->ops->alloc() is NULL\n"); + return -ENOSYS; + } + return domain->ops->alloc(domain, irq_base, nr_irqs, arg); } @@ -1347,11 +1352,6 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base, return -EINVAL; } - if (!domain->ops->alloc) { - pr_debug("domain->ops->alloc() is NULL\n"); - return -ENOSYS; - } - if (realloc && irq_base >= 0) { virq = irq_base; } else {