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 448ACE95A91 for ; Mon, 9 Oct 2023 13:14:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376895AbjJINO5 (ORCPT ); Mon, 9 Oct 2023 09:14:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376866AbjJINO4 (ORCPT ); Mon, 9 Oct 2023 09:14:56 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50526DA for ; Mon, 9 Oct 2023 06:14:53 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E09EAC433C8; Mon, 9 Oct 2023 13:14:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696857293; bh=0UDTGHjVIIkEyzudL1RfBtRtHfsQd28mx4BP/tNn/JE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tXTaR1UwNoBhvG17/t+Q6A44HI3pXt03RNlxNfVdzOtLZC5GmT5WJVc/HAFboJL8N hXYDOU8+Yo5oMM6RNyeIWtBI7PjLZGm0A9et348QncwRDjSuS2O7PaSCiHq1Zfszvm MEQcxWV1u9YY9jAUlaQItvXUuKDCyCV5MxzMcrxY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, luosili , Namjae Jeon , Steve French Subject: [PATCH 6.5 162/163] ksmbd: fix race condition from parallel smb2 lock requests Date: Mon, 9 Oct 2023 15:02:06 +0200 Message-ID: <20231009130128.474689115@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231009130124.021290599@linuxfoundation.org> References: <20231009130124.021290599@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon commit 75ac9a3dd65f7eab4d12b0a0f744234b5300a491 upstream. There is a race condition issue between parallel smb2 lock request. Time + Thread A | Thread A smb2_lock | smb2_lock | insert smb_lock to lock_list | spin_unlock(&work->conn->llist_lock) | | | spin_lock(&conn->llist_lock); | kfree(cmp_lock); | // UAF! | list_add(&smb_lock->llist, &rollback_list) + This patch swaps the line for adding the smb lock to the rollback list and adding the lock list of connection to fix the race issue. Reported-by: luosili Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/server/smb2pdu.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -7029,10 +7029,6 @@ skip: ksmbd_debug(SMB, "would have to wait for getting lock\n"); - spin_lock(&work->conn->llist_lock); - list_add_tail(&smb_lock->clist, - &work->conn->lock_list); - spin_unlock(&work->conn->llist_lock); list_add(&smb_lock->llist, &rollback_list); argv = kmalloc(sizeof(void *), GFP_KERNEL); @@ -7063,9 +7059,6 @@ skip: if (work->state != KSMBD_WORK_ACTIVE) { list_del(&smb_lock->llist); - spin_lock(&work->conn->llist_lock); - list_del(&smb_lock->clist); - spin_unlock(&work->conn->llist_lock); locks_free_lock(flock); if (work->state == KSMBD_WORK_CANCELLED) { @@ -7087,19 +7080,16 @@ skip: } list_del(&smb_lock->llist); - spin_lock(&work->conn->llist_lock); - list_del(&smb_lock->clist); - spin_unlock(&work->conn->llist_lock); release_async_work(work); goto retry; } else if (!rc) { + list_add(&smb_lock->llist, &rollback_list); spin_lock(&work->conn->llist_lock); list_add_tail(&smb_lock->clist, &work->conn->lock_list); list_add_tail(&smb_lock->flist, &fp->lock_list); spin_unlock(&work->conn->llist_lock); - list_add(&smb_lock->llist, &rollback_list); ksmbd_debug(SMB, "successful in taking lock\n"); } else { goto out;