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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
This commit is contained in:
Adam Thomas 2013-02-02 22:35:08 +00:00 committed by Artem Bityutskiy
parent 2928f0d0c5
commit 8afd500cb5
2 changed files with 6 additions and 1 deletions
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5
fs/ubifs/orphan.c
View File

@ -126,13 +126,14 @@ void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum)
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 @@ static void erase_deleted(struct ubifs_info *c)
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 @@ static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
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,

2
fs/ubifs/ubifs.h
View File

@ -905,6 +905,7 @@ struct ubifs_budget_req {
* @inum: inode number
* @new: %1 => added since the last commit, otherwise %0
* @cmt: %1 => commit pending, otherwise %0
* @del: %1 => delete pending, otherwise %0
*/
struct ubifs_orphan {
struct rb_node rb;
@ -915,6 +916,7 @@ struct ubifs_orphan {
ino_t inum;
unsigned new:1;
unsigned cmt:1;
unsigned del:1;
};
/**