From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Darren Kenny <darren.kenny@oracle.com>

Date: Fri, 23 Oct 2020 09:49:59 +0000

Subject: [PATCH] kern/partition: Check for NULL before dereferencing input

 string

There is the possibility that the value of str comes from an external

source and continuing to use it before ever checking its validity is

wrong. So, needs fixing.

Additionally, drop unneeded part initialization.

Fixes: CID 292444

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

---

 grub-core/kern/partition.c | 5 ++++-

 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/grub-core/kern/partition.c b/grub-core/kern/partition.c

index 2c401b866c4..3068c4dcac0 100644

--- a/grub-core/kern/partition.c

+++ b/grub-core/kern/partition.c

@@ -109,11 +109,14 @@ grub_partition_map_probe (const grub_partition_map_t partmap,

 grub_partition_t

 grub_partition_probe (struct grub_disk *disk, const char *str)

 {

-  grub_partition_t part = 0;

+  grub_partition_t part;

   grub_partition_t curpart = 0;

   grub_partition_t tail;

   const char *ptr;

+  if (str == NULL)

+    return 0;

+

   part = tail = disk->partition;

   for (ptr = str; *ptr;)