From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37C08C6FD18 for ; Tue, 18 Apr 2023 12:48:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232068AbjDRMsX (ORCPT ); Tue, 18 Apr 2023 08:48:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232052AbjDRMsN (ORCPT ); Tue, 18 Apr 2023 08:48:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6AEC15A09 for ; Tue, 18 Apr 2023 05:48:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EC77A633B8 for ; Tue, 18 Apr 2023 12:48:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D7ADC433D2; Tue, 18 Apr 2023 12:48:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681822085; bh=4W3YW/6YXbIjFW1mncF+GkSRi3En8StVLKgiFgm1tz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tofVC1UZO701ixDxhmZM0fV63zPqhE9Ey3xHCiSBe+HydoCUl6zyjwHT6VDJtQ21k k4kDZg9MyL2+P/1bycVdhEzKMLS3ZB/4b0xR4UP2Z70Us8IzsSXRvQISVDfAicRMW+ vJ41IdtFT2anT32taBlPup9B/1MWE5b4NIwidOdA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luiz Augusto von Dentz Subject: [PATCH 6.2 017/139] Bluetooth: hci_conn: Fix possible UAF Date: Tue, 18 Apr 2023 14:21:22 +0200 Message-Id: <20230418120314.312711588@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120313.725598495@linuxfoundation.org> References: <20230418120313.725598495@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Luiz Augusto von Dentz commit 5dc7d23e167e2882ef118456ceccd57873e876d8 upstream. This fixes the following trace: ================================================================== BUG: KASAN: slab-use-after-free in hci_conn_del+0xba/0x3a0 Write of size 8 at addr ffff88800208e9c8 by task iso-tester/31 CPU: 0 PID: 31 Comm: iso-tester Not tainted 6.3.0-rc2-g991aa4a69a47 #4716 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.1-2.fc36 04/01/2014 Call Trace: dump_stack_lvl+0x1d/0x70 print_report+0xce/0x610 ? __virt_addr_valid+0xd4/0x150 ? hci_conn_del+0xba/0x3a0 kasan_report+0xdd/0x110 ? hci_conn_del+0xba/0x3a0 hci_conn_del+0xba/0x3a0 hci_conn_hash_flush+0xf2/0x120 hci_dev_close_sync+0x388/0x920 hci_unregister_dev+0x122/0x260 vhci_release+0x4f/0x90 __fput+0x102/0x430 task_work_run+0xf1/0x160 ? __pfx_task_work_run+0x10/0x10 ? mark_held_locks+0x24/0x90 exit_to_user_mode_prepare+0x170/0x180 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x4e/0x90 entry_SYSCALL_64_after_hwframe+0x70/0xda Fixes: 0f00cd322d22 ("Bluetooth: Free potentially unfreed SCO connection") Link: https://syzkaller.appspot.com/bug?extid=8bb72f86fc823817bc5d Cc: Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_conn.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1049,6 +1049,17 @@ struct hci_conn *hci_conn_add(struct hci return conn; } +static bool hci_conn_unlink(struct hci_conn *conn) +{ + if (!conn->link) + return false; + + conn->link->link = NULL; + conn->link = NULL; + + return true; +} + int hci_conn_del(struct hci_conn *conn) { struct hci_dev *hdev = conn->hdev; @@ -1060,15 +1071,16 @@ int hci_conn_del(struct hci_conn *conn) cancel_delayed_work_sync(&conn->idle_work); if (conn->type == ACL_LINK) { - struct hci_conn *sco = conn->link; - if (sco) { - sco->link = NULL; + struct hci_conn *link = conn->link; + + if (link) { + hci_conn_unlink(conn); /* Due to race, SCO connection might be not established * yet at this point. Delete it now, otherwise it is * possible for it to be stuck and can't be deleted. */ - if (sco->handle == HCI_CONN_HANDLE_UNSET) - hci_conn_del(sco); + if (link->handle == HCI_CONN_HANDLE_UNSET) + hci_conn_del(link); } /* Unacked frames */ @@ -1084,7 +1096,7 @@ int hci_conn_del(struct hci_conn *conn) struct hci_conn *acl = conn->link; if (acl) { - acl->link = NULL; + hci_conn_unlink(conn); hci_conn_drop(acl); } @@ -2436,6 +2448,12 @@ void hci_conn_hash_flush(struct hci_dev c->state = BT_CLOSED; hci_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM); + + /* Unlink before deleting otherwise it is possible that + * hci_conn_del removes the link which may cause the list to + * contain items already freed. + */ + hci_conn_unlink(c); hci_conn_del(c); } }