[PATCH] elf: accept elf files without section header table

[Mathieu Mirmont]

It isn't an error for an elf executable to be lacking a section header
table. In this case we should just be returning shnum = 0.

According to the elf(5) manual page:
"
e_shoff  This member holds the section header table's file offset in
          bytes. If the file has no section header table, this member
          holds zero.
"

Signed-off-by: Mathieu Mirmont <mat@neutrality.ch>
---
 grub-core/kern/elfXX.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/grub-core/kern/elfXX.c b/grub-core/kern/elfXX.c
index aabf4b9d7..fe4ffb261 100644
--- a/grub-core/kern/elfXX.c
+++ b/grub-core/kern/elfXX.c
@@ -220,12 +220,12 @@ grub_elfXX_get_shnum (ElfXX_Ehdr *e, ElfXX_Shnum 
*shnum)
   if (e == NULL)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("NULL pointer passed 
for elf header"));

+  if (e->e_shoff == 0)
+    return GRUB_ERR_NONE;
+
   *shnum = e->e_shnum;
   if (*shnum == SHN_UNDEF)
     {
-      if (e->e_shoff == 0)
-       
return grub_error (GRUB_ERR_BAD_NUMBER, N_("invalid section header 
table offset in e_shoff"));
-
       s = (ElfXX_Shdr *) ((grub_uint8_t *) e + e->e_shoff);
       *shnum = s->sh_size;
       if (*shnum < SHN_LORESERVE)
--
2.30.2

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