Am 2022-04-13 um 03:36 schrieb Dan Carpenter:
If lookup_event_by_id() returns a NULL "ev" pointer then the
spin_lock(&ev->lock) will crash. This was detected by Smatch:
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_events.c:644 kfd_set_event()
error: we previously assumed 'ev' could be null (see line 639)
Fixes: 5273e82c5f47 ("drm/amdkfd: Improve concurrency of event handling")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
The patch is
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
I will apply it to amd-staging-drm-next. Thank you!
---
drivers/gpu/drm/amd/amdkfd/kfd_events.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
index 0fef24b0b915..15570e72a5dd 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
@@ -634,14 +634,19 @@ int kfd_set_event(struct kfd_process *p, uint32_t event_id)
rcu_read_lock();
ev = lookup_event_by_id(p, event_id);
+ if (!ev) {
+ ret = -EINVAL;
+ goto unlock_rcu;
+ }
spin_lock(&ev->lock);
- if (ev && event_can_be_cpu_signaled(ev))
+ if (event_can_be_cpu_signaled(ev))
set_event(ev);
else
ret = -EINVAL;
spin_unlock(&ev->lock);
+unlock_rcu:
rcu_read_unlock();
return ret;
}
@@ -660,14 +665,19 @@ int kfd_reset_event(struct kfd_process *p, uint32_t event_id)
rcu_read_lock();
ev = lookup_event_by_id(p, event_id);
+ if (!ev) {
+ ret = -EINVAL;
+ goto unlock_rcu;
+ }
spin_lock(&ev->lock);
- if (ev && event_can_be_cpu_signaled(ev))
+ if (event_can_be_cpu_signaled(ev))
reset_event(ev);
else
ret = -EINVAL;
spin_unlock(&ev->lock);
+unlock_rcu:
rcu_read_unlock();
return ret;
