loader/multiboot: fix unintended sign extension

Found by: Coveruty scan.
CID: 73700, 73763

diff --git a/grub-core/loader/multiboot_elfxx.c b/grub-core/loader/multiboot_elfxx.c
index 6a220bdc17bb38b20241a16bf0fbda0791ab7d7e..a7bebcb3c8a96d0a437f41cba95aa3319f9fb0cf 100644 (file)
--- a/grub-core/loader/multiboot_elfxx.c
+++ b/grub-core/loader/multiboot_elfxx.c
@@ -72,7 +72,7 @@ CONCAT(grub_multiboot_load_elf, XX) (grub_file_t file, const char *filename, voi
     return grub_error (GRUB_ERR_UNKNOWN_OS, N_("this ELF file is not of the right type"));
 
   /* FIXME: Should we support program headers at strange locations?  */
-  if (ehdr->e_phoff + ehdr->e_phnum * ehdr->e_phentsize > MULTIBOOT_SEARCH)
+  if (ehdr->e_phoff + (grub_uint32_t) ehdr->e_phnum * ehdr->e_phentsize > MULTIBOOT_SEARCH)
     return grub_error (GRUB_ERR_BAD_OS, "program header at a too high offset");
 
   phdr_base = (char *) buffer + ehdr->e_phoff;