[PATCH] drm/radeon: Use kvfree instead of kfree in radeon_gpu_reset

[Dawei Feng <dawei.feng@seu.edu.cn>]

radeon_ring_backup() internally allocates ring_data buffers using
kvmalloc_array(), which may use vmalloc() for large allocations. Using
kfree() to release vmalloc-backed ring_data buffers in
radeon_gpu_reset() will lead to memory corruption.

Use kvfree() to safely handle both kmalloc and vmalloc allocations.

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1-rc3.

Runtime validation was not attempted because a targeted reproducer for
this GPU reset error path was not available. Compile-tested only.

Fixes: 2098105ec65c ("drm: drop drm_[cm]alloc* helpers")
Cc: stable@vger.kernel.org
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>
---
 drivers/gpu/drm/radeon/radeon_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 705c012fcf9e..1f0f0d0eb673 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1800,7 +1800,7 @@ int radeon_gpu_reset(struct radeon_device *rdev)
 					    ring_sizes[i], ring_data[i]);
 		} else {
 			radeon_fence_driver_force_completion(rdev, i);
-			kfree(ring_data[i]);
+			kvfree(ring_data[i]);
 		}
 	}
 
-- 
2.34.1