This is a note to let you know that I've just added the patch titled
dm btree: add a defensive bounds check to insert_at()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-btree-add-a-defensive-bounds-check-to-insert_at.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7272347c3654861790c730ad174afb3c64758c01
Author: Joe Thornber <ejt@xxxxxxxxxx>
Date: Fri Dec 10 13:44:13 2021 +0000
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: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index fa9039a53ae5c..23b1d22f693c1 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;
--
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