[PATCH] xfs: avoid double-free in xfs_attr_node_addname

[Eric Sandeen <sandeen@xxxxxxxxxx>]

xfs_attr_node_addname()'s error handling tests whether it
should free "state" in the out: error handling label:

out:
        if (state)
                xfs_da_state_free(state);

but an earlier free doesn't set state to NULL afterwards; this
could lead to a double free.  Fix it by setting state to NULL
after it's freed.

This was found by Coverity.

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---

Note: Exact same patch should hit xfsprogs - I could send another,
or maybe SGI can just apply it in both trees?

Thanks,
-Eric

diff --git a/fs/xfs/xfs_attr.c b/fs/xfs/xfs_attr.c
index 20fe3fe..aaff8a9 100644
--- a/fs/xfs/xfs_attr.c
+++ b/fs/xfs/xfs_attr.c
@@ -1260,6 +1260,7 @@ restart:
                         * have been a b-tree.
                         */
                        xfs_da_state_free(state);
+                       state = NULL;
                        xfs_bmap_init(args->flist, args->firstblock);
                        error = xfs_attr3_leaf_to_node(args);
                        if (!error) {