Re: [PATCH 1/1] pxe: simplify label_boot()

On Mon, Nov 15, 2021 at 8:26 PM Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:

Coverity CID 131256 indicates a possible buffer overflow in label_boot(). This would only occur if the size of the downloaded file would exceed 4 GiB. But anyway we can simplify the code by using snprintf() and checking the return value.

Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com

boot/pxe_utils.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/boot/pxe_utils.c b/boot/pxe_utils.c index a7a84f26c1..5841561bdf 100644 --- a/boot/pxe_utils.c +++ b/boot/pxe_utils.c @@ -465,11 +465,10 @@ static int label_boot(struct pxe_context *ctx, struct pxe_label *label) }

            initrd_addr_str = env_get("ramdisk_addr_r");

•           strcpy(initrd_filesize, simple_xtoa(size));
  

•           strncpy(initrd_str, initrd_addr_str, 18);
  

•           strcat(initrd_str, ":");
  

•           strncat(initrd_str, initrd_filesize, 9);
  

•           size = snprintf(initrd_str, sizeof(initrd_str), "%s:%lx",
  

•                           initrd_addr_str, size);
  

•           if (size >= sizeof(initrd_str))
  

•                   return 1;
    }
  
    if (get_relfile_envaddr(ctx, label->kernel, "kernel_addr_r",
  

-- 2.32.0

Reviewed-by: Ramon Fried rfried.dev@gmail.com