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| author | Adam Thomas <adamthomas1111@gmail.com> | 2013-02-02 22:35:08 +0000 |
|---|---|---|
| committer | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2013-02-04 12:31:48 +0200 |
| commit | 8afd500cb52a5d00bab4525dd5a560d199f979b9 (patch) | |
| tree | 91ee2f6917c1f84300308dc6e659865cae89a3cc /fs/ubifs | |
| parent | 2928f0d0c5ebd6c9605c0d98207a44376387c298 (diff) | |
| download | lwn-8afd500cb52a5d00bab4525dd5a560d199f979b9.tar.gz lwn-8afd500cb52a5d00bab4525dd5a560d199f979b9.zip | |
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
Diffstat (limited to 'fs/ubifs')
| -rw-r--r-- | fs/ubifs/orphan.c | 5 | ||||
| -rw-r--r-- | fs/ubifs/ubifs.h | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c index 8534d9c6492f..ba32da3fe08a 100644 --- a/fs/ubifs/orphan.c +++ b/fs/ubifs/orphan.c @@ -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, diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index c16fff7271d3..b2babce4d70f 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -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; }; /** |