You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
100 lines
3.4 KiB
100 lines
3.4 KiB
From 37c0eb05cdcc64c28d31c4ebd300f14d5239d05e Mon Sep 17 00:00:00 2001
|
|
From: Daniel Axtens <dja@axtens.net>
|
|
Date: Mon, 18 Jan 2021 16:49:44 +1100
|
|
Subject: [PATCH] fs/nilfs2: Don't search children if provided number is too
|
|
large
|
|
|
|
NILFS2 reads the number of children a node has from the node. Unfortunately,
|
|
that's not trustworthy. Check if it's beyond what the filesystem permits and
|
|
reject it if so.
|
|
|
|
This blocks some OOB reads. I'm not sure how controllable the read is and what
|
|
could be done with invalidly read data later on.
|
|
|
|
Signed-off-by: Daniel Axtens <dja@axtens.net>
|
|
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
|
|
Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
|
|
---
|
|
grub-core/fs/nilfs2.c | 38 +++++++++++++++++++++++---------------
|
|
1 file changed, 23 insertions(+), 15 deletions(-)
|
|
|
|
diff --git a/grub-core/fs/nilfs2.c b/grub-core/fs/nilfs2.c
|
|
index fee2242..43ac1ad 100644
|
|
--- a/grub-core/fs/nilfs2.c
|
|
+++ b/grub-core/fs/nilfs2.c
|
|
@@ -416,14 +416,34 @@ grub_nilfs2_btree_node_get_key (struct grub_nilfs2_btree_node *node,
|
|
}
|
|
|
|
static inline int
|
|
-grub_nilfs2_btree_node_lookup (struct grub_nilfs2_btree_node *node,
|
|
+grub_nilfs2_btree_node_nchildren_max (struct grub_nilfs2_data *data,
|
|
+ struct grub_nilfs2_btree_node *node)
|
|
+{
|
|
+ int node_children_max = ((NILFS2_BLOCK_SIZE (data) -
|
|
+ sizeof (struct grub_nilfs2_btree_node) -
|
|
+ NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /
|
|
+ (sizeof (grub_uint64_t) + sizeof (grub_uint64_t)));
|
|
+
|
|
+ return (node->bn_flags & NILFS_BTREE_NODE_ROOT) ? 3 : node_children_max;
|
|
+}
|
|
+
|
|
+static inline int
|
|
+grub_nilfs2_btree_node_lookup (struct grub_nilfs2_data *data,
|
|
+ struct grub_nilfs2_btree_node *node,
|
|
grub_uint64_t key, int *indexp)
|
|
{
|
|
grub_uint64_t nkey;
|
|
int index, low, high, s;
|
|
|
|
low = 0;
|
|
+
|
|
high = grub_le_to_cpu16 (node->bn_nchildren) - 1;
|
|
+ if (high >= grub_nilfs2_btree_node_nchildren_max (data, node))
|
|
+ {
|
|
+ grub_error (GRUB_ERR_BAD_FS, "too many children");
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
index = 0;
|
|
s = 0;
|
|
while (low <= high)
|
|
@@ -459,18 +479,6 @@ grub_nilfs2_btree_node_lookup (struct grub_nilfs2_btree_node *node,
|
|
return s == 0;
|
|
}
|
|
|
|
-static inline int
|
|
-grub_nilfs2_btree_node_nchildren_max (struct grub_nilfs2_data *data,
|
|
- struct grub_nilfs2_btree_node *node)
|
|
-{
|
|
- int node_children_max = ((NILFS2_BLOCK_SIZE (data) -
|
|
- sizeof (struct grub_nilfs2_btree_node) -
|
|
- NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /
|
|
- (sizeof (grub_uint64_t) + sizeof (grub_uint64_t)));
|
|
-
|
|
- return (node->bn_flags & NILFS_BTREE_NODE_ROOT) ? 3 : node_children_max;
|
|
-}
|
|
-
|
|
static inline grub_uint64_t *
|
|
grub_nilfs2_btree_node_dptrs (struct grub_nilfs2_data *data,
|
|
struct grub_nilfs2_btree_node *node)
|
|
@@ -517,7 +525,7 @@ grub_nilfs2_btree_lookup (struct grub_nilfs2_data *data,
|
|
node = grub_nilfs2_btree_get_root (inode);
|
|
level = grub_nilfs2_btree_get_level (node);
|
|
|
|
- found = grub_nilfs2_btree_node_lookup (node, key, &index);
|
|
+ found = grub_nilfs2_btree_node_lookup (data, node, key, &index);
|
|
ptr = grub_nilfs2_btree_node_get_ptr (data, node, index);
|
|
if (need_translate)
|
|
ptr = grub_nilfs2_dat_translate (data, ptr);
|
|
@@ -538,7 +546,7 @@ grub_nilfs2_btree_lookup (struct grub_nilfs2_data *data,
|
|
}
|
|
|
|
if (!found)
|
|
- found = grub_nilfs2_btree_node_lookup (node, key, &index);
|
|
+ found = grub_nilfs2_btree_node_lookup (data, node, key, &index);
|
|
else
|
|
index = 0;
|
|
|
|
--
|
|
2.14.2
|
|
|
|
|