Messages in this thread Patch in this message |  | | Date | Fri, 25 Aug 2017 15:14:09 +0300 | From | Dan Carpenter <> | Subject | [PATCH v3] irqdomain: Prevent Oops in irq_domain_push_irq() |
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This code generates a Smatch warning:
kernel/irq/irqdomain.c:1511 irq_domain_push_irq() warn: variable dereferenced before check 'root_irq_data' (see line 1508)
irq_get_irq_data() does sometimes return NULL pointers so this seems like a real bug. Let's fix this bug by moving the check for NULL earlier.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- v2: Redo changelog. v3: Redo changelog again. Make it imperative.
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index b9c688944429..e84b7056bb08 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1505,10 +1505,10 @@ int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg) if (WARN_ON(!irq_domain_is_hierarchy(domain))) return -EINVAL; - if (domain->parent != root_irq_data->domain) + if (!root_irq_data) return -EINVAL; - if (!root_irq_data) + if (domain->parent != root_irq_data->domain) return -EINVAL; child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL,
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