From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Strengthen our checking of the AGI unlinked pointers when we start to
use them for updating the metadata.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
---
fs/xfs/xfs_inode.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 8c4a1d198de8..9c17ae95b18f 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1938,6 +1938,7 @@ xfs_iunlink(
struct xfs_buf *agibp;
struct xfs_buf *ibp;
struct xfs_perag *pag;
+ xfs_agino_t next_agino;
xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
@@ -1954,13 +1955,18 @@ xfs_iunlink(
agi = XFS_BUF_TO_AGI(agibp);
/*
- * Get the index into the agi hash table for the
- * list this inode will go on.
+ * Get the index into the agi hash table for the list this inode will
+ * go on. Make sure the pointer isn't garbage and that this inode
+ * isn't already on the list.
*/
- ASSERT(agi->agi_unlinked[bucket_index]);
- ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
+ next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
+ if (next_agino == agino ||
+ !xfs_verify_agino_or_null(mp, agno, next_agino)) {
+ error = -EFSCORRUPTED;
+ return error;
+ }
- if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
+ if (next_agino != NULLAGINO) {
/*
* There is already another inode in the bucket we need
* to add ourselves to. Add us at the front of the list.
@@ -2030,18 +2036,18 @@ xfs_iunlink_remove(
agi = XFS_BUF_TO_AGI(agibp);
/*
- * Get the index into the agi hash table for the
- * list this inode will go on.
+ * Get the index into the agi hash table for the list this inode will
+ * go on. Make sure the head pointer isn't garbage.
*/
- if (!xfs_verify_agino(mp, agno,
- be32_to_cpu(agi->agi_unlinked[bucket_index]))) {
+ next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
+ if (!xfs_verify_agino(mp, agno, next_agino)) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
agi, sizeof(*agi));
error = -EFSCORRUPTED;
goto out;
}
- if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
+ if (next_agino == agino) {
/*
* We're at the head of the list. Get the inode's on-disk
* buffer to see if there is anyone after us on the list.
@@ -2083,7 +2089,6 @@ xfs_iunlink_remove(
/*
* We need to search the list for the inode being freed.
*/
- next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
last_ibp = NULL;
while (next_agino != agino) {
struct xfs_imap imap;
