drm/amdgpu: add missing size check in amdgpu_debugfs_gprwave_read()

commit 4d75b9468021c73108b4439794d69e892b1d24e3 upstream.

Avoid a possible buffer overflow if size is larger than 4K.

Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit f5d873f5825b40d886d03bd2aede91d4cf002434)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 49711776b3516d672d2195639a75f0115652d0c5..2ca7a5d5ea64bb70fef2233868f272295ae1ba8e 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -401,7 +401,7 @@ static ssize_t amdgpu_debugfs_regs_didt_write(struct file *f, const char __user
        ssize_t result = 0;
        int r;
 
-       if (size & 0x3 || *pos & 0x3)
+       if (size > 4096 || size & 0x3 || *pos & 0x3)
                return -EINVAL;
 
        if (!adev->didt_wreg)