dm btree: add a defensive bounds check to insert_at()

[ Upstream commit 85bca3c05b ]

Corrupt metadata could trigger an out of bounds write.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Joe Thornber 2021-12-10 13:44:13 +00:00 committed by Greg Kroah-Hartman
parent eafd73401a
commit 74b16f895b
1 changed files with 5 additions and 3 deletions

View File

@ -83,14 +83,16 @@ void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
}
static int insert_at(size_t value_size, struct btree_node *node, unsigned index,
uint64_t key, void *value)
__dm_written_to_disk(value)
uint64_t key, void *value)
__dm_written_to_disk(value)
{
uint32_t nr_entries = le32_to_cpu(node->header.nr_entries);
uint32_t max_entries = le32_to_cpu(node->header.max_entries);
__le64 key_le = cpu_to_le64(key);
if (index > nr_entries ||
index >= le32_to_cpu(node->header.max_entries)) {
index >= max_entries ||
nr_entries >= max_entries) {
DMERR("too many entries in btree node for insert");
__dm_unbless_for_disk(value);
return -ENOMEM;