Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.4 65/73] dm btree: add a defensive bounds check to insert_at() | Date | Mon, 17 Jan 2022 21:44:24 -0500 |
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From: Joe Thornber <ejt@redhat.com>
[ Upstream commit 85bca3c05b6cca31625437eedf2060e846c4bbad ]
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> --- drivers/md/persistent-data/dm-btree.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c index 8aae0624a2971..6383afb88f319 100644 --- a/drivers/md/persistent-data/dm-btree.c +++ b/drivers/md/persistent-data/dm-btree.c @@ -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; -- 2.34.1
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