svn commit: r359147 - head/stand/common

[Toomas Soome]

Author: tsoome
Date: Thu Mar 19 17:27:08 2020
New Revision: 359147
URL: https://svnweb.freebsd.org/changeset/base/359147

Log:
  loader: misaligned access of dos_partition structure
  
  armv7 crash due to misligned access of dos_partition dp_start field.
  
  Allocate and make copy of dos_partition array to make sure the data
  is aligned.
  
  Reported by:	marklmi at yahoo.com

Modified:
  head/stand/common/part.c

Modified: head/stand/common/part.c
==============================================================================
--- head/stand/common/part.c	Thu Mar 19 17:20:50 2020	(r359146)
+++ head/stand/common/part.c	Thu Mar 19 17:27:08 2020	(r359147)
@@ -654,6 +654,7 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sect
 	int has_ext;
 #endif
 	table = NULL;
+	dp = NULL;
 	buf = malloc(sectorsize);
 	if (buf == NULL)
 		return (NULL);
@@ -708,7 +709,11 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sect
 		goto out;
 	}
 	/* Check that we have PMBR. Also do some validation. */
-	dp = (struct dos_partition *)(buf + DOSPARTOFF);
+	dp = malloc(NDOSPART * sizeof(struct dos_partition));
+	if (dp == NULL)
+		goto out;
+	bcopy(buf + DOSPARTOFF, dp, NDOSPART * sizeof(struct dos_partition));
+
 	/*
 	 * In mac we can have PMBR partition in hybrid MBR;
 	 * that is, MBR partition which has DOSPTYP_PMBR entry defined as
@@ -770,6 +775,7 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sect
 #endif /* LOADER_MBR_SUPPORT */
 #endif /* LOADER_MBR_SUPPORT || LOADER_GPT_SUPPORT */
 out:
+	free(dp);
 	free(buf);
 	return (table);
 }