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Commit 052f6401 authored by Joe Thornber's avatar Joe Thornber Committed by Greg Kroah-Hartman
Browse files

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



[ Upstream commit 85bca3c05b6cca31625437eedf2060e846c4bbad ]

Corrupt metadata could trigger an out of bounds write.

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent aaefb183

drivers/md/persistent-data/dm-btree.c

+5 −3
Original line number Diff line number Diff line
@@ -87,10 +87,12 @@ static int insert_at(size_t value_size, struct btree_node *node, unsigned index, 
	__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;