dma-buf: Replace strlcpy() with strscpy()

strlcpy() reads the entire source buffer first. This read may exceed
the destination size limit. This is both inefficient and can lead
to linear read overflows if a source string is not NUL-terminated[1].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116191409.work.634-kees@kernel.org
Signed-off-by: Christian König <christian.koenig@amd.com>
This commit is contained in:
Kees Cook 2023-11-16 11:14:10 -08:00 committed by Christian König
parent 9f5ac1969d
commit a323242804

View File

@ -46,12 +46,12 @@ static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
{
struct dma_buf *dmabuf;
char name[DMA_BUF_NAME_LEN];
size_t ret = 0;
ssize_t ret = 0;
dmabuf = dentry->d_fsdata;
spin_lock(&dmabuf->name_lock);
if (dmabuf->name)
ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN);
ret = strscpy(name, dmabuf->name, sizeof(name));
spin_unlock(&dmabuf->name_lock);
return dynamic_dname(buffer, buflen, "/%s:%s",