From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx> [ Upstream commit 87f2d1c662fa1761359fdf558246f97e484d177a ] 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 ... [<c06c23ff>] (gpiochip_hierarchy_irq_domain_alloc) [<c0462a89>] (__irq_domain_alloc_irqs) [<c0462dad>] (irq_create_fwspec_mapping) [<c06c2251>] (gpiochip_to_irq) [<c06c1c9b>] (gpiod_to_irq) [<bf973073>] (gpio_irqs_init [gpio_irqs]) [<bf974048>] (gpio_irqs_exit+0xecc/0xe84 [gpio_irqs]) Code: bad PC value Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200306174720.82604-1-alexander.sverdlin@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 480df36597206..c776b8e86fbcc 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1293,6 +1293,11 @@ 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); } @@ -1330,11 +1335,6 @@ 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 { -- 2.20.1
