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 649A8C7EE2F for ; Tue, 30 May 2023 13:00:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232445AbjE3NAE (ORCPT ); Tue, 30 May 2023 09:00:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232460AbjE3NAD (ORCPT ); Tue, 30 May 2023 09:00:03 -0400 Received: from mail-pf1-f174.google.com (mail-pf1-f174.google.com [209.85.210.174]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47A04127 for ; Tue, 30 May 2023 05:59:40 -0700 (PDT) Received: by mail-pf1-f174.google.com with SMTP id d2e1a72fcca58-64d44b198baso3022071b3a.0 for ; Tue, 30 May 2023 05:59:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685451497; x=1688043497; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=UpDRXdHm0h78ohDmltjWdcN9Fe7T0riwP8LaYasdf7w=; b=M11y3gv1ybw0WoKx2g+kUGBnJPawj9zyx3Yq4KPdCl0mC3j+RattQ5nz4q7Sw68ArQ h1vqjNN5cdRSK9M3atvdxrVrLaiGt8vs3HbeTVxnjrLIYmVQzwkOV7/8EzE+2F0ELBV3 4aF5ZtXZoUmuLsAI5+Va/CJpFZ2CGlM9PwmKamqP/Hby2YbyOrfsxdWn4coimfOdQoGZ PhX8A/SuquWF7gSgRtwbZXTLqp3XOZBqfA9hHoAClu6+OVegU8uCpTS/GrpiEDrJUV7i jr67rXOjjhzXzbI66l/a0x+alSS1qGnQJMph2wv+nvcWO5af2i8YV8AVIg/CjYRymZgu sf2A== X-Gm-Message-State: AC+VfDyk9+iwSILxu2khFGmEQeHgp/vl70MaIemXwnu3jSpfUCMRtUv4 SGvAMB2rFRa8kypdSdOgxiFFnohy39U= X-Google-Smtp-Source: ACHHUZ7sxr5h1c9Fi2YKL4cBQclvtBzHxNWTU/Q2Pt0kdCjSn/X7FUOL+VJowc18ZdJgxS1n78QfTg== X-Received: by 2002:a05:6a00:2393:b0:64d:2a87:2596 with SMTP id f19-20020a056a00239300b0064d2a872596mr3698793pfc.10.1685451496698; Tue, 30 May 2023 05:58:16 -0700 (PDT) Received: from localhost.localdomain ([211.49.23.9]) by smtp.gmail.com with ESMTPSA id c17-20020aa78c11000000b0063afb08afeesm1605007pfd.67.2023.05.30.05.58.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 May 2023 05:58:16 -0700 (PDT) From: Namjae Jeon To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, senozhatsky@chromium.org, tom@talpey.com, atteh.mailbox@gmail.com, Namjae Jeon , Chih-Yen Chang Subject: [PATCH] ksmbd: fix out-of-bound read in parse_lease_state() Date: Tue, 30 May 2023 21:57:55 +0900 Message-Id: <20230530125757.12910-2-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230530125757.12910-1-linkinjeon@kernel.org> References: <20230530125757.12910-1-linkinjeon@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org This bug is in parse_lease_state, and it is caused by the missing check of `struct create_context`. When the ksmbd traverses the create_contexts, it doesn't check if the field of `NameOffset` and `Next` is valid, The KASAN message is following: [ 6.664323] BUG: KASAN: slab-out-of-bounds in parse_lease_state+0x7d/0x280 [ 6.664738] Read of size 2 at addr ffff888005c08988 by task kworker/0:3/103 ... [ 6.666644] Call Trace: [ 6.666796] [ 6.666933] dump_stack_lvl+0x33/0x50 [ 6.667167] print_report+0xcc/0x620 [ 6.667903] kasan_report+0xae/0xe0 [ 6.668374] kasan_check_range+0x35/0x1b0 [ 6.668621] parse_lease_state+0x7d/0x280 [ 6.668868] smb2_open+0xbe8/0x4420 [ 6.675137] handle_ksmbd_work+0x282/0x820 Use smb2_find_context_vals() to find smb2 create request lease context. smb2_find_context_vals validate create context fields. Reported-by: Chih-Yen Chang Tested-by: Chih-Yen Chang Signed-off-by: Namjae Jeon --- fs/smb/server/oplock.c | 66 +++++++++++++++--------------------------- 1 file changed, 24 insertions(+), 42 deletions(-) diff --git a/fs/smb/server/oplock.c b/fs/smb/server/oplock.c index db181bdad73a..844b303baf29 100644 --- a/fs/smb/server/oplock.c +++ b/fs/smb/server/oplock.c @@ -1415,56 +1415,38 @@ void create_lease_buf(u8 *rbuf, struct lease *lease) */ struct lease_ctx_info *parse_lease_state(void *open_req) { - char *data_offset; struct create_context *cc; - unsigned int next = 0; - char *name; - bool found = false; struct smb2_create_req *req = (struct smb2_create_req *)open_req; - struct lease_ctx_info *lreq = kzalloc(sizeof(struct lease_ctx_info), - GFP_KERNEL); + struct lease_ctx_info *lreq; + + cc = smb2_find_context_vals(req, SMB2_CREATE_REQUEST_LEASE, 4); + if (IS_ERR_OR_NULL(cc)) + return NULL; + + lreq = kzalloc(sizeof(struct lease_ctx_info), GFP_KERNEL); if (!lreq) return NULL; - data_offset = (char *)req + le32_to_cpu(req->CreateContextsOffset); - cc = (struct create_context *)data_offset; - do { - cc = (struct create_context *)((char *)cc + next); - name = le16_to_cpu(cc->NameOffset) + (char *)cc; - if (le16_to_cpu(cc->NameLength) != 4 || - strncmp(name, SMB2_CREATE_REQUEST_LEASE, 4)) { - next = le32_to_cpu(cc->Next); - continue; - } - found = true; - break; - } while (next != 0); + if (sizeof(struct lease_context_v2) == le32_to_cpu(cc->DataLength)) { + struct create_lease_v2 *lc = (struct create_lease_v2 *)cc; - if (found) { - if (sizeof(struct lease_context_v2) == le32_to_cpu(cc->DataLength)) { - struct create_lease_v2 *lc = (struct create_lease_v2 *)cc; - - memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); - lreq->req_state = lc->lcontext.LeaseState; - lreq->flags = lc->lcontext.LeaseFlags; - lreq->duration = lc->lcontext.LeaseDuration; - memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey, - SMB2_LEASE_KEY_SIZE); - lreq->version = 2; - } else { - struct create_lease *lc = (struct create_lease *)cc; + memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); + lreq->req_state = lc->lcontext.LeaseState; + lreq->flags = lc->lcontext.LeaseFlags; + lreq->duration = lc->lcontext.LeaseDuration; + memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey, + SMB2_LEASE_KEY_SIZE); + lreq->version = 2; + } else { + struct create_lease *lc = (struct create_lease *)cc; - memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); - lreq->req_state = lc->lcontext.LeaseState; - lreq->flags = lc->lcontext.LeaseFlags; - lreq->duration = lc->lcontext.LeaseDuration; - lreq->version = 1; - } - return lreq; + memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); + lreq->req_state = lc->lcontext.LeaseState; + lreq->flags = lc->lcontext.LeaseFlags; + lreq->duration = lc->lcontext.LeaseDuration; + lreq->version = 1; } - - kfree(lreq); - return NULL; + return lreq; } /** -- 2.25.1