UBIFS: fix double free of ubifs_orphan objects
The last orphan in the dnext list has its dnext set to NULL. Because
of that, ubifs_delete_orphan assumes that it is not on the dnext list
and frees it immediately instead ignoring it as a second delete. The
orphan is later freed again by erase_deleted.
This change adds an explicit flag to ubifs_orphan indicating whether
it is pending delete.
Signed-off-by: Adam Thomas <adamthomas1111@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c
index 8534d9c..ba32da3 100644
--- a/fs/ubifs/orphan.c
+++ b/fs/ubifs/orphan.c
@@ -126,13 +126,14 @@
else if (inum > o->inum)
p = p->rb_right;
else {
- if (o->dnext) {
+ if (o->del) {
spin_unlock(&c->orphan_lock);
dbg_gen("deleted twice ino %lu",
(unsigned long)inum);
return;
}
if (o->cmt) {
+ o->del = 1;
o->dnext = c->orph_dnext;
c->orph_dnext = o;
spin_unlock(&c->orphan_lock);
@@ -447,6 +448,7 @@
orphan = dnext;
dnext = orphan->dnext;
ubifs_assert(!orphan->new);
+ ubifs_assert(orphan->del);
rb_erase(&orphan->rb, &c->orph_tree);
list_del(&orphan->list);
c->tot_orphans -= 1;
@@ -536,6 +538,7 @@
rb_link_node(&orphan->rb, parent, p);
rb_insert_color(&orphan->rb, &c->orph_tree);
list_add_tail(&orphan->list, &c->orph_list);
+ orphan->del = 1;
orphan->dnext = c->orph_dnext;
c->orph_dnext = orphan;
dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,