From: Stefan Ring <stefanrin@gmail.com>
To: linux-xfs@vger.kernel.org
Cc: Stefan Ring <str@visotech.com>
Subject: [PATCH 2/2] xfs_metadump: Zap more stale data
Date: Thu, 11 Oct 2018 21:23:07 +0200 [thread overview]
Message-ID: <20181011192307.18553-3-stefanrin@gmail.com> (raw)
In-Reply-To: <20181011192307.18553-1-stefanrin@gmail.com>
From: Stefan Ring <str@visotech.com>
I have empirically found and tried to fix some places where stale data was not
properly zeroed out.
In the order of the code changes:
- The "freeindex" blocks in inode directories, from last entry to end of block.
- XFS_DIR{2,3}_LEAFN_MAGIC, from last entry to end of block.
- In btree format inodes before as well as after the btree pointers.
- In dev inodes, everything after the header.
---
db/metadump.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 98 insertions(+), 8 deletions(-)
diff --git a/db/metadump.c b/db/metadump.c
index ff96860d..c8213d41 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1421,12 +1421,49 @@ process_sf_attr(
memset(asfep, 0, XFS_DFORK_ASIZE(dip, mp) - ino_attr_size);
}
+static void
+process_dir_free_block(
+ char *block)
+{
+ struct xfs_dir2_free *free;
+ struct xfs_dir3_icfree_hdr freehdr;
+
+ if (!zero_stale_data)
+ return;
+
+ free = (struct xfs_dir2_free *)block;
+ M_DIROPS(mp)->free_hdr_from_disk(&freehdr, free);
+
+ switch (freehdr.magic) {
+ case XFS_DIR2_FREE_MAGIC:
+ case XFS_DIR3_FREE_MAGIC: {
+ __be16 *bests;
+ char *high;
+ int used;
+
+ /* Zero out space from end of bests[] to end of block */
+ bests = M_DIROPS(mp)->free_bests_p(free);
+ high = (char *)&bests[freehdr.nvalid];
+ used = high - (char*)free;
+ memset(high, 0, mp->m_dir_geo->blksize - used);
+ iocur_top->need_crc = 1;
+ break;
+ }
+ default:
+ if (show_warnings)
+ print_warning("invalid magic in dir inode %llu "
+ "free block",
+ (unsigned long long)cur_ino);
+ break;
+ }
+}
+
static void
process_dir_leaf_block(
char *block)
{
struct xfs_dir2_leaf *leaf;
- struct xfs_dir3_icleaf_hdr leafhdr;
+ struct xfs_dir3_icleaf_hdr leafhdr;
if (!zero_stale_data)
return;
@@ -1435,20 +1472,39 @@ process_dir_leaf_block(
leaf = (struct xfs_dir2_leaf *)block;
M_DIROPS(mp)->leaf_hdr_from_disk(&leafhdr, leaf);
- /* Zero out space from end of ents[] to bests */
- if (leafhdr.magic == XFS_DIR2_LEAF1_MAGIC ||
- leafhdr.magic == XFS_DIR3_LEAF1_MAGIC) {
+ switch (leafhdr.magic) {
+ case XFS_DIR2_LEAF1_MAGIC:
+ case XFS_DIR3_LEAF1_MAGIC: {
struct xfs_dir2_leaf_tail *ltp;
__be16 *lbp;
struct xfs_dir2_leaf_entry *ents;
char *free; /* end of ents */
+ /* Zero out space from end of ents[] to bests */
ents = M_DIROPS(mp)->leaf_ents_p(leaf);
free = (char *)&ents[leafhdr.count];
ltp = xfs_dir2_leaf_tail_p(mp->m_dir_geo, leaf);
lbp = xfs_dir2_leaf_bests_p(ltp);
memset(free, 0, (char *)lbp - free);
iocur_top->need_crc = 1;
+ break;
+ }
+ case XFS_DIR2_LEAFN_MAGIC:
+ case XFS_DIR3_LEAFN_MAGIC: {
+ struct xfs_dir2_leaf_entry *ents;
+ char *free;
+ int used;
+
+ /* Zero out space from end of ents[] to end of block */
+ ents = M_DIROPS(mp)->leaf_ents_p(leaf);
+ free = (char *)&ents[leafhdr.count];
+ used = free - (char*)leaf;
+ memset(free, 0, mp->m_dir_geo->blksize - used);
+ iocur_top->need_crc = 1;
+ break;
+ }
+ default:
+ break;
}
}
@@ -1499,7 +1555,7 @@ process_dir_data_block(
if (show_warnings)
print_warning(
"invalid magic in dir inode %llu block %ld",
- (long long)cur_ino, (long)offset);
+ (unsigned long long)cur_ino, (long)offset);
return;
}
@@ -1813,8 +1869,7 @@ process_single_fsb_objects(
switch (btype) {
case TYP_DIR2:
if (o >= mp->m_dir_geo->freeblk) {
- /* TODO, zap any stale data */
- break;
+ process_dir_free_block(dp);
} else if (o >= mp->m_dir_geo->leafblk) {
process_dir_leaf_block(dp);
} else {
@@ -2118,6 +2173,21 @@ process_btinode(
}
pp = XFS_BMDR_PTR_ADDR(dib, 1, maxrecs);
+
+ if (zero_stale_data) {
+ char *top;
+ int used;
+
+ /* Space before btree pointers */
+ top = (char*)XFS_BMDR_PTR_ADDR(dib, 1, nrecs);
+ memset(top, 0, (char*)pp - top);
+
+ /* Space after btree pointers */
+ top = (char*)&pp[nrecs];
+ used = top - (char*)dip;
+ memset(top, 0, mp->m_sb.sb_inodesize - used);
+ }
+
for (i = 0; i < nrecs; i++) {
xfs_agnumber_t ag;
xfs_agblock_t bno;
@@ -2201,6 +2271,24 @@ process_inode_data(
return 1;
}
+static int
+process_dev_inode(
+ xfs_dinode_t *dip)
+{
+ if (XFS_DFORK_NEXTENTS(dip, XFS_ATTR_FORK) ||
+ XFS_DFORK_NEXTENTS(dip, XFS_DATA_FORK)) {
+ if (show_warnings)
+ print_warning("inode %llu has unexpected extents",
+ (unsigned long long)cur_ino);
+ return 0;
+ } else {
+ int used = XFS_DFORK_DPTR(dip) - (char*)dip;
+
+ memset(XFS_DFORK_DPTR(dip), 0, mp->m_sb.sb_inodesize - used);
+ return 1;
+ }
+}
+
/*
* when we process the inode, we may change the data in the data and/or
* attribute fork if they are in short form and we are obfuscating names.
@@ -2253,7 +2341,9 @@ process_inode(
case S_IFREG:
success = process_inode_data(dip, TYP_DATA);
break;
- default: ;
+ default:
+ success = process_dev_inode(dip);
+ break;
}
nametable_clear();
--
2.14.4
next prev parent reply other threads:[~2018-10-12 2:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-11 19:23 [PATCH v2 0/2] Try to squash metadump data leaks Stefan Ring
2018-10-11 19:23 ` [PATCH 1/2] xfs_metadump: Extend zapping to multi fsb dir blocks Stefan Ring
2018-10-11 19:23 ` Stefan Ring [this message]
2018-10-11 19:44 [PATCH v3 0/2] Try to squash metadump data leaks Stefan Ring
2018-10-11 19:44 ` [PATCH 2/2] xfs_metadump: Zap more stale data Stefan Ring
2018-10-23 15:49 ` Darrick J. Wong
2018-10-25 16:42 ` Stefan Ring
2018-10-26 20:23 ` Stefan Ring
2018-10-26 5:32 ` Stefan Ring
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