malloc: Use overflow checking primitives where we do complex allocations

This attempts to fix the places where we do the following where
arithmetic_expr may include unvalidated data:

  X = grub_malloc(arithmetic_expr);

It accomplishes this by doing the arithmetic ahead of time using grub_add(),
grub_sub(), grub_mul() and testing for overflow before proceeding.

Among other issues, this fixes:
  - allocation of integer overflow in grub_video_bitmap_create()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_png_decode_image_header()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_squash_read_symlink()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_ext2_read_symlink()
    reported by Chris Coulson,
  - allocation of integer overflow in read_section_as_string()
    reported by Chris Coulson.

Fixes: CVE-2020-14309, CVE-2020-14310, CVE-2020-14311

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Peter Jones 2020-06-15 12:28:27 -04:00 committed by Daniel Kiper
parent f725fa7cb2
commit 3f05d693d1
23 changed files with 382 additions and 113 deletions

View file

@ -22,6 +22,7 @@
#include <grub/misc.h>
#include <grub/disk.h>
#include <grub/partition.h>
#include <grub/safemath.h>
#include <grub/dl.h>
#include <grub/types.h>
#include <grub/zfs/zfs.h>
@ -82,9 +83,13 @@ grub_zfs_add_key (grub_uint8_t *key_in,
int passphrase)
{
struct grub_zfs_wrap_key *key;
grub_size_t sz;
if (!passphrase && keylen > 32)
keylen = 32;
key = grub_malloc (sizeof (*key) + keylen);
if (grub_add (sizeof (*key), keylen, &sz))
return GRUB_ERR_OUT_OF_RANGE;
key = grub_malloc (sz);
if (!key)
return grub_errno;
key->is_passphrase = passphrase;