diff options
| author | Darrick J. Wong <djwong@kernel.org> | 2022-10-31 10:32:29 -0700 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2022-11-06 12:36:12 -0800 |
| commit | 7647d4ad37b8ee289bd7e12579a62929a47d72dc (patch) | |
| tree | 45752a4dd4e38e10ba38d9fe570fa9a2c8236eb1 | |
| parent | 44d8ee46fa320b7267247713c4321a2e12d7765d (diff) | |
xfs: make sure aglen never goes negative in xfs_refcount_adjust_extents
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 a refcount
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>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
| -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 64b910caafaa..831353ba96dc 100644 --- a/fs/xfs/libxfs/xfs_refcount.c +++ b/fs/xfs/libxfs/xfs_refcount.c @@ -986,15 +986,29 @@ 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, *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 |