commit a6d31caf4eaa453d3ec879f02163b3a515789b85
Author: Likhitha Korrapati <likhitha@linux.ibm.com>
Date:   Mon Sep 11 05:23:37 2023 -0500

    powerpc/nvram: Fix Segmentation fault issue in nvram-size.
    
    nvram-size option results in segmentation fault when the user
    specifies value larger than the default nvram size
    
    Without the patch:
    [root@xxx ~]# nvram --nvram-size 1048592
    nvram: WARNING: expected 1048592 bytes, but only read 15360!
    Segmentation fault (core dumped)
    
    Segmentation fault is caused because the phead->length is becoming 0.
    And because of this the p_start doesn't get updated which makes the
    while loop run infinitely resulting in segmentation fault.
    This patch adds a condition check for phead->length to avoid infinite
    while loop.
    
    With the patch:
    [root@xxx src]# ./nvram --nvram-size 1048592
    ./nvram: WARNING: expected 1048592 bytes, but only read 15360!
    [root@xxx src]# ./nvram --nvram-size 268435456
    ./nvram: WARNING: expected 268435456 bytes, but only read 15360!
    [root@xxx src]#
    
    Reported-by: Shirisha Ganta <shirisha@linux.ibm.com>
    Signed-off-by: Likhitha Korrapati <likhitha@linux.ibm.com>
    [tyreld: fixed up else block]
    Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>

diff --git a/src/nvram.c b/src/nvram.c
index 095e747..1987c3d 100644
--- a/src/nvram.c
+++ b/src/nvram.c
@@ -460,8 +460,12 @@ nvram_parse_partitions(struct nvram *nvram)
 	c_sum = checksum(phead);
 	if (c_sum != phead->checksum)
 	    warn_msg("this partition checksum should be %02x!\n", c_sum);
-	phead->length = be16toh(phead->length);
-	p_start += phead->length * NVRAM_BLOCK_SIZE;
+	if (phead->length != 0) {
+		phead->length = be16toh(phead->length);
+		p_start += phead->length * NVRAM_BLOCK_SIZE;
+	} else {
+		break;
+	}
     }
 
     if (verbose)