After a list_for_each_entry() loop, the list iterator is always non-NULL
so these conditions don't work. If the "waiter" is not found then this
results in an out of bounds access.
I have fixed it by introducing a new "found" variable. In one case, I
used an else statement for readability.
Fixes: 46e4b9ec4fa4 ("staging: vchiq_arm: use list_for_each_entry when accessing bulk_waiter_list")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
v2: rebase on latest linux-next
.../vc04_services/interface/vchiq_arm/vchiq_arm.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index 590415561b73..e6a9aab66f4a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -432,6 +432,7 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data,
struct vchiq_service *service;
enum vchiq_status status;
struct bulk_waiter_node *waiter = NULL;
+ bool found = false;
service = find_service_by_handle(handle);
if (!service)
@@ -445,12 +446,13 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data,
list_for_each_entry(waiter, &instance->bulk_waiter_list, list) {
if (waiter->pid == current->pid) {
list_del(&waiter->list);
+ found = true;
break;
}
}
mutex_unlock(&instance->bulk_waiter_list_mutex);
- if (waiter) {
+ if (found) {
struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
if (bulk) {
@@ -467,9 +469,7 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data,
spin_unlock(&bulk_waiter_spinlock);
}
}
- }
-
- if (!waiter) {
+ } else {
waiter = kzalloc(sizeof(struct bulk_waiter_node), GFP_KERNEL);
if (!waiter) {
vchiq_log_error(vchiq_core_log_level,
@@ -952,6 +952,7 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
{
struct vchiq_service *service;
struct bulk_waiter_node *waiter = NULL;
+ bool found = false;
void *userdata;
int status = 0;
int ret;
@@ -975,11 +976,12 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
list) {
if (waiter->pid == current->pid) {
list_del(&waiter->list);
+ found = true;
break;
}
}
mutex_unlock(&instance->bulk_waiter_list_mutex);
- if (!waiter) {
+ if (!found) {
vchiq_log_error(vchiq_arm_log_level,
"no bulk_waiter found for pid %d",
current->pid);
--
2.28.0
