From nobody Mon Sep 29 21:09:36 2025 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 3A3C9C32757 for ; Mon, 15 Aug 2022 22:28:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350423AbiHOW0o (ORCPT ); Mon, 15 Aug 2022 18:26:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350071AbiHOWR2 (ORCPT ); Mon, 15 Aug 2022 18:17:28 -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 17DF56111E; Mon, 15 Aug 2022 12:40:48 -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 0A884611DD; Mon, 15 Aug 2022 19:40:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5C60C433D6; Mon, 15 Aug 2022 19:40:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660592445; bh=pEg1GtkK46egxGc6yKcxjHl9FylMjMsYz88rOu1nqA0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z3N4gOamyieIoO3OyUVJCNC0gX5X3xi6737uTRtZPHZyx6x2euhR9l1SCVkN+QPPg 5VKcuXAi4Eru3nqUgO2YOszgGhRQKSu4UwMISJdtg3A7Q6xVxMb6G7QE7wJ1lPBm8W bcBC00eYLTnzbK3GvPu2WkA/tX+bOZUpS0wmGcX0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Namjae Jeon , Hyunchul Lee , Steve French , zdi-disclosures@trendmicro.com Subject: [PATCH 5.19 0111/1157] ksmbd: fix use-after-free bug in smb2_tree_disconect Date: Mon, 15 Aug 2022 19:51:07 +0200 Message-Id: <20220815180444.071124057@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Namjae Jeon commit cf6531d98190fa2cf92a6d8bbc8af0a4740a223c upstream. smb2_tree_disconnect() freed the struct ksmbd_tree_connect, but it left the dangling pointer. It can be accessed again under compound requests. This bug can lead an oops looking something link: [ 1685.468014 ] BUG: KASAN: use-after-free in ksmbd_tree_conn_disconnect+0x= 131/0x160 [ksmbd] [ 1685.468068 ] Read of size 4 at addr ffff888102172180 by task kworker/1:2= /4807 ... [ 1685.468130 ] Call Trace: [ 1685.468132 ] [ 1685.468135 ] dump_stack_lvl+0x49/0x5f [ 1685.468141 ] print_report.cold+0x5e/0x5cf [ 1685.468145 ] ? ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468157 ] kasan_report+0xaa/0x120 [ 1685.468194 ] ? ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468206 ] __asan_report_load4_noabort+0x14/0x20 [ 1685.468210 ] ksmbd_tree_conn_disconnect+0x131/0x160 [ksmbd] [ 1685.468222 ] smb2_tree_disconnect+0x175/0x250 [ksmbd] [ 1685.468235 ] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 1685.468247 ] process_one_work+0x778/0x11c0 [ 1685.468251 ] ? _raw_spin_lock_irq+0x8e/0xe0 [ 1685.468289 ] worker_thread+0x544/0x1180 [ 1685.468293 ] ? __cpuidle_text_end+0x4/0x4 [ 1685.468297 ] kthread+0x282/0x320 [ 1685.468301 ] ? process_one_work+0x11c0/0x11c0 [ 1685.468305 ] ? kthread_complete_and_exit+0x30/0x30 [ 1685.468309 ] ret_from_fork+0x1f/0x30 Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17816 Signed-off-by: Namjae Jeon Reviewed-by: Hyunchul Lee Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/ksmbd/smb2pdu.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2043,6 +2043,7 @@ int smb2_tree_disconnect(struct ksmbd_wo =20 ksmbd_close_tree_conn_fds(work); ksmbd_tree_conn_disconnect(sess, tcon); + work->tcon =3D NULL; return 0; }