6.5-stable review patch. If anyone has any objections, please let me know.
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From: Pauli Virtanen pav@iki.fi
[ 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@iki.fi Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/hci_sync.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-)
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);