On 2026-07-06 15:18, Yongqiang Sun
wrote:
total_cwsr_size was computed in 32-bit before being used as a BO/SVM
allocation size.
With large ctx_save_restore_area_size and debug_memory_size
multiplied by the XCC count, the product can wrap,
yielding an undersized CWSR save area that firmware later overruns.
Promote total_cwsr_size to u64 and use check_add_overflow()/
check_mul_overflow() in both kfd_queue_acquire_buffers() and
kfd_queue_release_buffers().
Signed-off-by: Yongqiang Sun <Yongqiang.Sun@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_queue.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_queue.c b/drivers/gpu/drm/amd/amdkfd/kfd_queue.c
index 9d4838461168..4b1c1e379244 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_queue.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_queue.c
@@ -23,6 +23,7 @@
*/
#include <linux/slab.h>
+#include <linux/overflow.h>
#include "kfd_priv.h"
#include "kfd_topology.h"
#include "kfd_svm.h"
@@ -235,7 +236,7 @@ int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_prope
struct kfd_topology_device *topo_dev;
u64 expected_queue_size;
struct amdgpu_vm *vm;
- u32 total_cwsr_size;
+ u64 total_cwsr_size;
int err;
topo_dev = kfd_topology_device_by_id(pdd->dev->id);
@@ -308,8 +309,15 @@ int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_prope
goto out_err_unreserve;
}
- total_cwsr_size = (properties->ctx_save_restore_area_size +
- topo_dev->node_props.debug_memory_size) * NUM_XCC(pdd->dev->xcc_mask);
+ if (check_add_overflow(properties->ctx_save_restore_area_size,
+ topo_dev->node_props.debug_memory_size,
+ &total_cwsr_size) ||
Because properties->ctx_save_restore_area_size and topo_dev->node_props.debug_memory_size are u32,
total_cwsr_size is u64 now, check_add_overflow will never
overflow to return true, use typecast u64 add instead
total_cwsr_size = (u64)properties->ctx_save_restore_area_size + topo_dev->node_props.debug_memory_size;
+ check_mul_overflow(total_cwsr_size,
+ (u64)NUM_XCC(pdd->dev->xcc_mask),
Since total_cwsr_size is u64, NUM_XCC(pdd->dev->xcc_mask) will promote to u64 as well, this u64 typecast is not needed.
+ &total_cwsr_size)) {
+ err = -EINVAL;
+ goto out_err_unreserve;
+ }
total_cwsr_size = ALIGN(total_cwsr_size, PAGE_SIZE);
err = kfd_queue_buffer_get(vm, (void *)properties->ctx_save_restore_area_address,
@@ -344,7 +352,7 @@ int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_prope
int kfd_queue_release_buffers(struct kfd_process_device *pdd, struct queue_properties *properties)
{
struct kfd_topology_device *topo_dev;
- u32 total_cwsr_size;
+ u64 total_cwsr_size;
kfd_queue_buffer_put(&properties->wptr_bo);
kfd_queue_buffer_put(&properties->rptr_bo);
@@ -355,8 +363,13 @@ int kfd_queue_release_buffers(struct kfd_process_device *pdd, struct queue_prope
topo_dev = kfd_topology_device_by_id(pdd->dev->id);
if (!topo_dev)
return -EINVAL;
- total_cwsr_size = (properties->ctx_save_restore_area_size +
- topo_dev->node_props.debug_memory_size) * NUM_XCC(pdd->dev->xcc_mask);
+ if (check_add_overflow(properties->ctx_save_restore_area_size,
+ topo_dev->node_props.debug_memory_size,
+ &total_cwsr_size) ||
+ check_mul_overflow(total_cwsr_size,
+ (u64)NUM_XCC(pdd->dev->xcc_mask),
+ &total_cwsr_size))
Do the same change as above kfd_queue_acquire_buffers.
Regards,
Philip
+ return -EINVAL;
total_cwsr_size = ALIGN(total_cwsr_size, PAGE_SIZE);
kfd_queue_buffer_svm_put(pdd, properties->ctx_save_restore_area_address, total_cwsr_size);