[PATCH 2/4] xfs_repair: fix unaligned accesses

Eric Sandeen
2015-10-09T00:25:32Z

This fixes some unaligned accesses spotted by libubsan in repair.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
repair/dinode.c | 19 +++++++++----------
repair/prefetch.c | 4 ++--
2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/repair/dinode.c b/repair/dinode.c
index f78f907..44bbb8f 100644
--- a/repair/dinode.c
+++ b/repair/dinode.c
@@ -960,13 +960,13 @@ _("bad numrecs 0 in inode %" PRIu64 " bmap btree root block\n"),
* btree, we'd do it right here. For now, if there's a
* problem, we'll bail out and presumably clear the inode.
*/
- if (!verify_dfsbno(mp, be64_to_cpu(pp[i]))) {
+ if (!verify_dfsbno(mp, get_unaligned_be64(&pp[i]))) {
do_warn(_("bad bmap btree ptr 0x%llx in ino %" PRIu64 "\n"),
- (unsigned long long) be64_to_cpu(pp[i]), lino);
+ get_unaligned_be64(&pp[i]), lino);
return(1);
}

- if (scan_lbtree(be64_to_cpu(pp[i]), level, scan_bmapbt, type,
+ if (scan_lbtree(get_unaligned_be64(&pp[i]), level, scan_bmapbt, type,
whichfork, lino, tot, nex, blkmapp, &cursor,
1, check_dups, magic, &xfs_bmbt_buf_ops))
return(1);
@@ -977,25 +977,24 @@ _("bad numrecs 0 in inode %" PRIu64 " bmap btree root block\n"),
* blocks but the parent hasn't been updated
*/
if (!check_dups && cursor.level[level-1].first_key !=
- be64_to_cpu(pkey[i].br_startoff)) {
+ get_unaligned_be64(&pkey[i].br_startoff)) {
if (!no_modify) {
do_warn(
_("correcting key in bmbt root (was %llu, now %" PRIu64") in inode "
"%" PRIu64" %s fork\n"),
- (unsigned long long)
- be64_to_cpu(pkey[i].br_startoff),
+ get_unaligned_be64(&pkey[i].br_startoff),
cursor.level[level-1].first_key,
XFS_AGINO_TO_INO(mp, agno, ino),
forkname);
*dirty = 1;
- pkey[i].br_startoff = cpu_to_be64(
- cursor.level[level-1].first_key);
+ put_unaligned_be64(
+ cpu_to_be64(cursor.level[level-1].first_key),
+ &pkey[i].br_startoff);
} else {
do_warn(
_("bad key in bmbt root (is %llu, would reset to %" PRIu64 ") in inode "
"%" PRIu64 " %s fork\n"),
- (unsigned long long)
- be64_to_cpu(pkey[i].br_startoff),
+ get_unaligned_be64(&pkey[i].br_startoff),
cursor.level[level-1].first_key,
XFS_AGINO_TO_INO(mp, agno, ino),
forkname);
diff --git a/repair/prefetch.c b/repair/prefetch.c
index 32ec55e..52238ca 100644
--- a/repair/prefetch.c
+++ b/repair/prefetch.c
@@ -330,7 +330,7 @@ pf_scanfunc_bmap(
pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);

for (i = 0; i < numrecs; i++) {
- dbno = be64_to_cpu(pp[i]);
+ dbno = get_unaligned_be64(&pp[i]);
if (!verify_dfsbno(mp, dbno))
return 0;
if (!pf_scan_lbtree(dbno, level, isadir, args, pf_scanfunc_bmap))
@@ -372,7 +372,7 @@ pf_read_btinode(
pp = XFS_BMDR_PTR_ADDR(dib, 1, xfs_bmdr_maxrecs(dsize, 0));

for (i = 0; i < numrecs; i++) {
- dbno = be64_to_cpu(pp[i]);
+ dbno = get_unaligned_be64(&pp[i]);
if (!verify_dfsbno(mp, dbno))
break;
if (!pf_scan_lbtree(dbno, level, isadir, args, pf_scanfunc_bmap))
--
1.7.1