The patch below does not apply to the 6.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.5.y git checkout FETCH_HEAD git cherry-pick -x a239110ee8e0b0aafa265f0d54f7a16744855e70 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023102019-shove-stagnant-982e@gregkh' --subject-prefix 'PATCH 6.5.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a239110ee8e0b0aafa265f0d54f7a16744855e70 Mon Sep 17 00:00:00 2001 From: Pauli Virtanen <pav@xxxxxx> Date: Sat, 30 Sep 2023 15:53:32 +0300 Subject: [PATCH] Bluetooth: hci_sync: always check if connection is alive before deleting 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> diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index d06e07a0ea5a..a15ab0b874a9 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -5369,6 +5369,7 @@ 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) { @@ -5399,24 +5400,15 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason) hci_dev_unlock(hdev); return 0; 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; @@ -5428,7 +5420,13 @@ 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);
