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authorDarrick J. Wong <djwong@kernel.org>2022-10-25 18:18:21 -0700
committerDarrick J. Wong <djwong@kernel.org>2022-10-31 08:58:20 -0700
commitf850995f60e49818093ef5e477cdb0ff2c11a0a4 (patch)
treec2c25e75c9fded537a94a85dfbc973a871cfa998 /fs/xfs/libxfs
parentxfs: dump corrupt recovered log intent items to dmesg consistently (diff)
downloadlinux-dev-f850995f60e49818093ef5e477cdb0ff2c11a0a4.tar.xz
linux-dev-f850995f60e49818093ef5e477cdb0ff2c11a0a4.zip
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>
Diffstat (limited to 'fs/xfs/libxfs')
-rw-r--r--fs/xfs/libxfs/xfs_refcount.c20
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