6.7-stable review patch. If anyone has any objections, please let me know.
------------------
From: Luben Tuikov <ltuikov89@xxxxxxxxx>
[ Upstream commit 2bbe6ab2be53858507f11f99f856846d04765ae3 ]
If we're given a malformed entity in drm_sched_entity_init()--shouldn't
happen, but we verify--with out-of-bounds priority value, we set it to an
allowed value. Fix the expression which sets this limit.
Signed-off-by: Luben Tuikov <ltuikov89@xxxxxxxxx>
Fixes: 56e449603f0ac5 ("drm/sched: Convert the GPU scheduler to variable number of run-queues")
Link: https://patchwork.freedesktop.org/patch/msgid/20231123122422.167832-2-ltuikov89@xxxxxxxxx
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Link: https://lore.kernel.org/r/dbb91dbe-ef77-4d79-aaf9-2adb171c1d7a@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/scheduler/sched_entity.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index 409e4256f6e7..0a7a7e4ad8d1 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -81,12 +81,15 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
*/
pr_warn("%s: called with uninitialized scheduler\n", __func__);
} else if (num_sched_list) {
- /* The "priority" of an entity cannot exceed the number
- * of run-queues of a scheduler.
+ /* The "priority" of an entity cannot exceed the number of run-queues of a
+ * scheduler. Protect against num_rqs being 0, by converting to signed.
*/
- if (entity->priority >= sched_list[0]->num_rqs)
- entity->priority = max_t(u32, sched_list[0]->num_rqs,
- DRM_SCHED_PRIORITY_MIN);
+ if (entity->priority >= sched_list[0]->num_rqs) {
+ drm_err(sched_list[0], "entity with out-of-bounds priority:%u num_rqs:%u\n",
+ entity->priority, sched_list[0]->num_rqs);
+ entity->priority = max_t(s32, (s32) sched_list[0]->num_rqs - 1,
+ (s32) DRM_SCHED_PRIORITY_MIN);
+ }
entity->rq = sched_list[0]->sched_rq[entity->priority];
}
--
2.43.0
