mirrors/scoutfs
1
0
Fork 0
mirror of https://github.com/versity/scoutfs.git synced 2026-01-07 04:26:29 +00:00
Code Issues Packages Projects Releases Wiki Activity

scoutfs: add assertions for bad treap offsets

Browse Source 
The wild casting in the treap code can cause memory corruption if it's
fed bad offsets.  Add some assertions so that we can see when this is
happening.

Signed-off-by: Zach Brown <zab@versity.com>
This commit is contained in:
Zach Brown
2016-04-14 13:15:12 -07:00
parent 3e5eeaa80c
commit 1c284af854
1 changed files with 23 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
kmod/src/treap.c
View File

@@ -29,22 +29,44 @@
* The caller is responsible for locking access to the tree.
*/
/*
* treap nodes are embedded in btree items. Their offset is relative to
* the treap root which is embedded in the btree block header. Their
* offset can't have the item overlap the btree block header, nor can
* the item fall off the end of the block.
*/
static void bug_on_bad_node_off(u16 off)
{
BUG_ON(off < (sizeof(struct scoutfs_btree_block) -
offsetof(struct scoutfs_btree_block, treap) +
offsetof(struct scoutfs_btree_item, tnode)));
BUG_ON(off > (SCOUTFS_BLOCK_SIZE - sizeof(struct scoutfs_btree_item) +
offsetof(struct scoutfs_btree_item, tnode)));
}
static struct scoutfs_treap_node *off_node(struct scoutfs_treap_root *root,
__le16 off)
{
if (!off)
return NULL;
bug_on_bad_node_off(le16_to_cpu(off));
return (void *)root + le16_to_cpu(off);
}
static __le16 node_off(struct scoutfs_treap_root *root,
struct scoutfs_treap_node *node)
{
u16 off;
if (!node)
return 0;
return cpu_to_le16((char *)node - (char *)root);
off = (char *)node - (char *)root;
bug_on_bad_node_off(off);
return cpu_to_le16(off);
}
/*