git: 51ddd2851e4a - stable/12 - loader: misaligned access of dos_partition structure

The branch stable/12 has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=51ddd2851e4a36e28cf78dfe06125723f7d2b113

commit 51ddd2851e4a36e28cf78dfe06125723f7d2b113
Author:     Toomas Soome <tsoome@FreeBSD.org>
AuthorDate: 2020-03-19 17:27:08 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2021-10-08 01:15:59 +0000

    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.
    
    (cherry picked from commit 87d8d5ea3dd0a8ad2c0468660805017d6d45d937)
---
 stand/common/part.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/stand/common/part.c b/stand/common/part.c
index b84678efd3cc..69df57abb175 100644
--- a/stand/common/part.c
+++ b/stand/common/part.c
@@ -662,6 +662,7 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sectorsize,
 	int has_ext;
 #endif
 	table = NULL;
+	dp = NULL;
 	buf = malloc(sectorsize);
 	if (buf == NULL)
 		return (NULL);
@@ -716,7 +717,11 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sectorsize,
 		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
@@ -778,6 +783,7 @@ ptable_open(void *dev, uint64_t sectors, uint16_t sectorsize,
 #endif /* LOADER_MBR_SUPPORT */
 #endif /* LOADER_MBR_SUPPORT || LOADER_GPT_SUPPORT */
 out:
+	free(dp);
 	free(buf);
 	return (table);
 }