[PATCH 3/4] xfs_logprint: fix some unaligned accesses

Eric Sandeen
2015-10-09T00:25:54Z

This routine had a fair bit of gyration to avoid unaligned accesses,
but didn't fix them all. Fix some more spotted at runtime by libubsan.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
logprint/log_misc.c | 18 +++++++++++++++---
repair/btree.c | 1 +
2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/logprint/log_misc.c b/logprint/log_misc.c
index d76145c..6cd249a 100644
--- a/logprint/log_misc.c
+++ b/logprint/log_misc.c
@@ -325,7 +325,11 @@ xlog_print_trans_buffer(char **ptr, int len, int *i, int num_ops)
}
super_block = 0;
} else if (be32_to_cpu(*(__be32 *)(*ptr)) == XFS_AGI_MAGIC) {
- agi = (xfs_agi_t *)(*ptr);
+ struct xfs_agi agi_s;
+
+ /* memmove because *ptr may not be 8-byte aligned */
+ memmove(&agi_s, *ptr, sizeof(struct xfs_agi));
+ agi = &agi_s;
printf(_("AGI Buffer: XAGI "));
/*
* v4 filesystems only contain the fields before the uuid.
@@ -375,7 +379,11 @@ xlog_print_trans_buffer(char **ptr, int len, int *i, int num_ops)
}
}
} else if (be32_to_cpu(*(__be32 *)(*ptr)) == XFS_AGF_MAGIC) {
- agf = (xfs_agf_t *)(*ptr);
+ struct xfs_agf agf_s;
+
+ /* memmove because *ptr may not be 8-byte aligned */
+ memmove(&agf_s, *ptr, sizeof(struct xfs_agf));
+ agf = &agf_s;
printf(_("AGF Buffer: XAGF "));
/*
* v4 filesystems only contain the fields before the uuid.
@@ -408,7 +416,11 @@ xlog_print_trans_buffer(char **ptr, int len, int *i, int num_ops)
be32_to_cpu(agf->agf_longest));
}
} else if (be32_to_cpu(*(__be32 *)(*ptr)) == XFS_DQUOT_MAGIC) {
- dq = (xfs_disk_dquot_t *)(*ptr);
+ struct xfs_disk_dquot dq_s;
+
+ /* memmove because *ptr may not be 8-byte aligned */
+ memmove(&dq_s, *ptr, sizeof(struct xfs_disk_dquot));
+ dq = &dq_s;
printf(_("DQUOT Buffer: DQ "));
if (be32_to_cpu(head->oh_len) <
sizeof(xfs_disk_dquot_t)) {
diff --git a/repair/btree.c b/repair/btree.c
index 66fb40b..e31e67a 100644
--- a/repair/btree.c
+++ b/repair/btree.c
@@ -230,6 +230,7 @@ btree_get_next(
}
if (level == 0) {
if (key) {
+ /* XXXX what if index past MAX? What if no next? */
cur->index++;
*key = btree_key_of_cursor(cur, root->height);
cur->index--;
--
1.7.1