2023-08-07 12:06:22

by Min Li

[permalink] [raw]
Subject: [PATCH] Bluetooth: Fix potential use-after-free when clear keys

Similar to commit c5d2b6fa26b5 ("Bluetooth: Fix use-after-free in
hci_remove_ltk/hci_remove_irk"). We can not access k after kfree_rcu()
call.

Fixes: d7d41682efc2 ("Bluetooth: Fix Suspicious RCU usage warnings")
Signed-off-by: Min Li <[email protected]>
---
net/bluetooth/hci_core.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index a856b1051d35..bae8a9919dbe 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1074,9 +1074,9 @@ void hci_uuids_clear(struct hci_dev *hdev)

void hci_link_keys_clear(struct hci_dev *hdev)
{
- struct link_key *key;
+ struct link_key *key, *tmp;

- list_for_each_entry(key, &hdev->link_keys, list) {
+ list_for_each_entry_safe(key, tmp, &hdev->link_keys, list) {
list_del_rcu(&key->list);
kfree_rcu(key, rcu);
}
@@ -1084,9 +1084,9 @@ void hci_link_keys_clear(struct hci_dev *hdev)

void hci_smp_ltks_clear(struct hci_dev *hdev)
{
- struct smp_ltk *k;
+ struct smp_ltk *k, *tmp;

- list_for_each_entry(k, &hdev->long_term_keys, list) {
+ list_for_each_entry_safe(k, tmp, &hdev->long_term_keys, list) {
list_del_rcu(&k->list);
kfree_rcu(k, rcu);
}
@@ -1094,9 +1094,9 @@ void hci_smp_ltks_clear(struct hci_dev *hdev)

void hci_smp_irks_clear(struct hci_dev *hdev)
{
- struct smp_irk *k;
+ struct smp_irk *k, *tmp;

- list_for_each_entry(k, &hdev->identity_resolving_keys, list) {
+ list_for_each_entry_safe(k, tmp, &hdev->identity_resolving_keys, list) {
list_del_rcu(&k->list);
kfree_rcu(k, rcu);
}
@@ -1104,9 +1104,9 @@ void hci_smp_irks_clear(struct hci_dev *hdev)

void hci_blocked_keys_clear(struct hci_dev *hdev)
{
- struct blocked_key *b;
+ struct blocked_key *b, *tmp;

- list_for_each_entry(b, &hdev->blocked_keys, list) {
+ list_for_each_entry_safe(b, tmp, &hdev->blocked_keys, list) {
list_del_rcu(&b->list);
kfree_rcu(b, rcu);
}
--
2.34.1