diff options
| author | Darrick J. Wong <djwong@kernel.org> | 2022-10-11 13:31:57 -0700 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2022-10-14 14:16:29 -0700 |
| commit | 3466c3207de0de28be92222b794529020cbbb927 (patch) | |
| tree | 9221ed74901e1f1a174e063d9f8028584af61c97 | |
| parent | 94d1833bd71af2c42a558a162db0d0c52e9780fa (diff) | |
xfs: make sure aglen never goes negative in xfs_refcount_adjust_extentsrefcount-cow-domain_2022-10-14
Prior to calling xfs_refcount_adjust_extents, we trimmed agbno/aglen
such that the end of the range would not be in the middle of the record.
If this is no longer the case, something is seriously wrong with the
btree. Bail out with a corruption error.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| -rw-r--r-- | fs/xfs/libxfs/xfs_refcount.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c index 1ce59ac9b533..e5a382e1550e 100644 --- a/fs/xfs/libxfs/xfs_refcount.c +++ b/fs/xfs/libxfs/xfs_refcount.c @@ -1040,15 +1040,29 @@ xfs_refcount_adjust_extents( (*agbno) += tmp.rc_blockcount; (*aglen) -= tmp.rc_blockcount; + /* Stop if there's nothing left to modify */ + if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) + break; + + /* Move the cursor to the start of ext. */ error = xfs_refcount_lookup_ge(cur, XFS_RCDOM_SHARED, *agbno, &found_rec); if (error) goto out_error; } - /* Stop if there's nothing left to modify */ - if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) - break; + /* + * A previous step trimmed agbno/aglen such that the end of the + * range would not be in the middle of the record. If this is + * no longer the case, something is seriously wrong with the + * btree. Make sure we never feed the synthesized record into + * the processing loop below. + */ + if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_blockcount == 0) || + XFS_IS_CORRUPT(cur->bc_mp, ext.rc_blockcount > *aglen)) { + error = -EFSCORRUPTED; + goto out_error; + } /* * Adjust the reference count and either update the tree |