[PATCH v4] ieee1275 : Add a check for invalid partition number

From: Avnish Chouhan <avnish@linux.ibm.com>
To: grub-devel@gnu.org
Cc: daniel.kiper@oracle.com, Avnish Chouhan <avnish@linux.ibm.com>
Subject: [PATCH v4] ieee1275 : Add a check for invalid partition number
Date: Mon, 12 Jan 2026 23:20:14 +0530	[thread overview]
Message-ID: <20260112175014.89194-1-avnish@linux.ibm.com> (raw)

Add a check for invalid partition number. grub_strtoul() may fail
in several scenarios like invalid input, overflow, etc. Lack of
proper check may lead to unexpected failures in the code further.

Signed-off-by: Avnish Chouhan <avnish@linux.ibm.com>
---
 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);
+      unsigned long partno;
+      char *endptr;
+
+      partno = grub_strtoul (partition, &endptr, 0);
+      grub_errno = GRUB_ERR_NONE;
+      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"), "%zu", partno);
     }
   else
     *optr = '\0';
-- 
2.50.1 (Apple Git-155)


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