This is a note to let you know that I've just added the patch titled
Bluetooth: hci_sync: always check if connection is alive before deleting
to the 6.5-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:
bluetooth-hci_sync-always-check-if-connection-is-ali.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b7bbe510c0454e4829cb714de5dd786eae4e42f1
Author: Pauli Virtanen <pav@xxxxxx>
Date: Sat Sep 30 15:53:32 2023 +0300
Bluetooth: hci_sync: always check if connection is alive before deleting
[ Upstream commit a239110ee8e0b0aafa265f0d54f7a16744855e70 ]
In hci_abort_conn_sync it is possible that conn is deleted concurrently
by something else, also e.g. when waiting for hdev->lock. This causes
double deletion of the conn, so UAF or conn_hash.list corruption.
Fix by having all code paths check that the connection is still in
conn_hash before deleting it, while holding hdev->lock which prevents
any races.
Log (when powering off while BAP streaming, occurs rarely):
=======================================================================
kernel BUG at lib/list_debug.c:56!
...
? __list_del_entry_valid (lib/list_debug.c:56)
hci_conn_del (net/bluetooth/hci_conn.c:154) bluetooth
hci_abort_conn_sync (net/bluetooth/hci_sync.c:5415) bluetooth
? __pfx_hci_abort_conn_sync+0x10/0x10 [bluetooth]
? lock_release+0x1d5/0x3c0
? hci_disconnect_all_sync.constprop.0+0xb2/0x230 [bluetooth]
? __pfx_lock_release+0x10/0x10
? __kmem_cache_free+0x14d/0x2e0
hci_disconnect_all_sync.constprop.0+0xda/0x230 [bluetooth]
? __pfx_hci_disconnect_all_sync.constprop.0+0x10/0x10 [bluetooth]
? hci_clear_adv_sync+0x14f/0x170 [bluetooth]
? __pfx_set_powered_sync+0x10/0x10 [bluetooth]
hci_set_powered_sync+0x293/0x450 [bluetooth]
=======================================================================
Fixes: 94d9ba9f9888 ("Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync")
Signed-off-by: Pauli Virtanen <pav@xxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index d21127e992c0f..360813ab0c4db 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -5374,6 +5374,7 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason)
{
int err = 0;
u16 handle = conn->handle;
+ bool disconnect = false;
struct hci_conn *c;
switch (conn->state) {
@@ -5389,24 +5390,15 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason)
break;
case BT_OPEN:
case BT_BOUND:
- hci_dev_lock(hdev);
- hci_conn_failed(conn, reason);
- hci_dev_unlock(hdev);
- return 0;
+ break;
default:
- hci_dev_lock(hdev);
- conn->state = BT_CLOSED;
- hci_disconn_cfm(conn, reason);
- hci_conn_del(conn);
- hci_dev_unlock(hdev);
- return 0;
+ disconnect = true;
+ break;
}
hci_dev_lock(hdev);
- /* Check if the connection hasn't been cleanup while waiting
- * commands to complete.
- */
+ /* Check if the connection has been cleaned up concurrently */
c = hci_conn_hash_lookup_handle(hdev, handle);
if (!c || c != conn) {
err = 0;
@@ -5418,7 +5410,13 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason)
* or in case of LE it was still scanning so it can be cleanup
* safely.
*/
- hci_conn_failed(conn, reason);
+ if (disconnect) {
+ conn->state = BT_CLOSED;
+ hci_disconn_cfm(conn, reason);
+ hci_conn_del(conn);
+ } else {
+ hci_conn_failed(conn, reason);
+ }
unlock:
hci_dev_unlock(hdev);
