On Tue, Dec 12, 2023 at 01:20:20AM +0000, Justin Stitt wrote: > strncpy() is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > We don't need the NUL-padding behavior that strncpy() provides as vscsi > is NUL-allocated in ibmvscsis_probe() which proceeds to call > ibmvscsis_adapter_info(): > | vscsi = kzalloc(sizeof(*vscsi), GFP_KERNEL); > > ibmvscsis_probe() -> ibmvscsis_handle_crq() -> ibmvscsis_parse_command() > -> ibmvscsis_mad() -> ibmvscsis_process_mad() -> ibmvscsis_adapter_info() > > Following the same idea, `partition_name` is defiend as: > | static char partition_name[PARTITION_NAMELEN] = "UNKNOWN"; > ... which is NUL-padded already, meaning strscpy() is the best option. > > Considering the above, a suitable replacement is `strscpy` [2] due to > the fact that it guarantees NUL-termination on the destination buffer > without unnecessarily NUL-padding. > > However, for cap->name and info let's use strscpy_pad as they are > allocated via dma_alloc_coherent(): > | cap = dma_alloc_coherent(&vscsi->dma_dev->dev, olen, &token, > | GFP_ATOMIC); > & > | info = dma_alloc_coherent(&vscsi->dma_dev->dev, sizeof(*info), &token, > | GFP_ATOMIC); > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@xxxxxxxxxxxxxxx > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> This looks good to me. The only question that I haven't seen an answer to from the maintainers is whether this is a __nonstring or not. It really looks like it should be a C String, so with that assumption: Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -Kees -- Kees Cook
