From: Juergen Gross Date: Thu, 23 Feb 2023 08:38:00 +0000 (+0100) Subject: irqdomain: Add missing NULL pointer check in irq_domain_create_hierarchy() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ad32ab9604f29827494024828f527228e84fbd2c;p=linux.git irqdomain: Add missing NULL pointer check in irq_domain_create_hierarchy() The recent switch to per-domain locking caused a NULL dereference in irq_domain_create_hierarchy(), as Xen code is calling msi_create_irq_domain() with a NULL parent pointer. Fix that by testing parent to be set before dereferencing it. For a non-existing parent the irqdomain's root will stay to point to itself. Fixes: 9dbb8e3452ab ("irqdomain: Switch to per-domain locking") Signed-off-by: Juergen Gross Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230223083800.31347-1-jgross@suse.com --- diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index aa5b7eeeceb8d..6522dfb2e49c4 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1172,7 +1172,8 @@ struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent, domain = __irq_domain_create(fwnode, 0, ~0, 0, ops, host_data); if (domain) { - domain->root = parent->root; + if (parent) + domain->root = parent->root; domain->parent = parent; domain->flags |= flags;