From e2327678732d78c90dec024e0ba4c9b65ca9cdd2 Mon Sep 17 00:00:00 2001 From: Marcelo Diop-Gonzalez Date: Thu, 13 Feb 2020 14:40:01 -0500 Subject: [PATCH] staging: vc04_services: Fix wrong early return in next_service_by_instance() If kref_get_unless_zero() fails, we should keep looking for the next service, since the callers of this function expect that a NULL return value means there are no more. Signed-off-by: Marcelo Diop-Gonzalez Link: https://lore.kernel.org/r/20200213194001.130110-1-marcgonzalez@google.com Signed-off-by: Greg Kroah-Hartman --- .../vc04_services/interface/vchiq_arm/vchiq_core.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c index d7d7f4d9d57f..edcd97373809 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c @@ -252,11 +252,15 @@ next_service_by_instance(struct vchiq_state *state, struct vchiq_service *service; rcu_read_lock(); - service = __next_service_by_instance(state, instance, pidx); - if (service && kref_get_unless_zero(&service->ref_count)) - service = rcu_pointer_handoff(service); - else - service = NULL; + while (1) { + service = __next_service_by_instance(state, instance, pidx); + if (!service) + break; + if (kref_get_unless_zero(&service->ref_count)) { + service = rcu_pointer_handoff(service); + break; + } + } rcu_read_unlock(); return service; }