On 1/12/26 08:29, Avnish Chouhan wrote:
Adding a check for invalid partition number. grub_strtoul() can fail
in several scenarios like invalid input, overflow, etc will result in
an invalid partition number which could lead to an undefined behavior.

Signed-off-by: Avnish Chouhan <[email protected]>
---
  grub-core/kern/ieee1275/openfw.c | 17 +++++++++++++++--
  1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/grub-core/kern/ieee1275/openfw.c b/grub-core/kern/ieee1275/openfw.c
index 3b492dd..f8ae515 100644
--- a/grub-core/kern/ieee1275/openfw.c
+++ b/grub-core/kern/ieee1275/openfw.c
@@ -512,7 +512,20 @@ grub_ieee1275_encode_devname (const char *path)
      }
    if (partition && partition[0])
      {
-      unsigned int partno = grub_strtoul (partition, 0, 0);
+      char *endptr;
+
+      unsigned long partno = grub_strtoul (partition, &endptr, 0);

I recommend setting the base instead of letting it be 0. An input string of "[" would be accepted as the number 43.

+      grub_errno = GRUB_ERR_NONE;

I believe grub_errno should be set before the call to strtoul() instead of after it. Setting grub_errno before would allow you to use it as part of your error checking below.

Regards,
Nicholas Vinson

+
+      if (*endptr != '\0' || partno > 65535 ||
+          (partno == 0 && ! grub_ieee1275_test_flag 
(GRUB_IEEE1275_FLAG_0_BASED_PARTITIONS)))
+        {
+          grub_free (partition);
+          grub_free (device);
+          grub_free (encoding);
+          grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid partition number"));
+          return NULL;
+        }
*optr++ = ','; @@ -520,7 +533,7 @@ grub_ieee1275_encode_devname (const char *path)
        /* GRUB partition 1 is OF partition 0.  */
        partno++;
- grub_snprintf (optr, sizeof ("XXXXXXXXXXXX"), "%d", partno);
+      grub_snprintf (optr, sizeof ("XXXXXXXXXXXX"), "%lu", partno);
      }
    else
      *optr = '\0';


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