There is no reason to allow for partial buffers from userspace in our debugfs. In this particular case callers will zero out the wr_buf but if callers in the future don't do that we might be looking at corrupt data. Linus puts it better than I can in https://lkml.org/lkml/2021/10/26/993 Signed-off-by: Harry Wentland <harry.wentland@xxxxxxx> --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c index 1a68a674913c..b30307ccff12 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c @@ -78,12 +78,10 @@ static int parse_write_buffer_into_params(char *wr_buf, uint32_t wr_buf_size, wr_buf_ptr = wr_buf; - r = copy_from_user(wr_buf_ptr, buf, wr_buf_size); - - /* r is bytes not be copied */ - if (r >= wr_buf_size) { - DRM_DEBUG_DRIVER("user data not be read\n"); - return -EINVAL; + /* r is bytes not be copied */ + if (copy_from_user(wr_buf_ptr, buf, wr_buf_size)) { + DRM_DEBUG_DRIVER("user data could not be read successfully\n"); + return -EFAULT; } /* check number of parameters. isspace could not differ space and \n */ -- 2.33.0
