From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C50B4168C5 for ; Mon, 8 May 2023 10:56:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C474C433EF; Mon, 8 May 2023 10:56:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683543364; bh=2IA3LRxmcobvDJKrnc/k/9wf85DpxfCYJwenP3llV9o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RNmVebb9KDWHjI2DOBPmAxF3Lir2Pu3lyvynPPcHZ/MwH7vGIUKm2bHSwrvtDnfCL eZRu1pD4GNEC/4Bo8fVt9vgQ3RKdFQsKkxfdT3z8jP7cVOoCXx7gkxvpPVOwpIHCrG TErKaz2Ul54ytWT++59n+IP99h53EJH4fRaotIUA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Namjae Jeon , Steve French , zdi-disclosures@trendmicro.com Subject: [PATCH 6.3 066/694] ksmbd: fix racy issue under cocurrent smb2 tree disconnect Date: Mon, 8 May 2023 11:38:21 +0200 Message-Id: <20230508094434.698854563@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094432.603705160@linuxfoundation.org> References: <20230508094432.603705160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Namjae Jeon commit 30210947a343b6b3ca13adc9bfc88e1543e16dd5 upstream. There is UAF issue under cocurrent smb2 tree disconnect. This patch introduce TREE_CONN_EXPIRE flags for tcon to avoid cocurrent access. Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-20592 Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/ksmbd/mgmt/tree_connect.c | 10 +++++++++- fs/ksmbd/mgmt/tree_connect.h | 3 +++ fs/ksmbd/smb2pdu.c | 3 ++- 3 files changed, 14 insertions(+), 2 deletions(-) --- a/fs/ksmbd/mgmt/tree_connect.c +++ b/fs/ksmbd/mgmt/tree_connect.c @@ -109,7 +109,15 @@ int ksmbd_tree_conn_disconnect(struct ks struct ksmbd_tree_connect *ksmbd_tree_conn_lookup(struct ksmbd_session *sess, unsigned int id) { - return xa_load(&sess->tree_conns, id); + struct ksmbd_tree_connect *tcon; + + tcon = xa_load(&sess->tree_conns, id); + if (tcon) { + if (test_bit(TREE_CONN_EXPIRE, &tcon->status)) + tcon = NULL; + } + + return tcon; } struct ksmbd_share_config *ksmbd_tree_conn_share(struct ksmbd_session *sess, --- a/fs/ksmbd/mgmt/tree_connect.h +++ b/fs/ksmbd/mgmt/tree_connect.h @@ -14,6 +14,8 @@ struct ksmbd_share_config; struct ksmbd_user; struct ksmbd_conn; +#define TREE_CONN_EXPIRE 1 + struct ksmbd_tree_connect { int id; @@ -25,6 +27,7 @@ struct ksmbd_tree_connect { int maximal_access; bool posix_extensions; + unsigned long status; }; struct ksmbd_tree_conn_status { --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2048,11 +2048,12 @@ int smb2_tree_disconnect(struct ksmbd_wo ksmbd_debug(SMB, "request\n"); - if (!tcon) { + if (!tcon || test_and_set_bit(TREE_CONN_EXPIRE, &tcon->status)) { struct smb2_tree_disconnect_req *req = smb2_get_msg(work->request_buf); ksmbd_debug(SMB, "Invalid tid %d\n", req->hdr.Id.SyncId.TreeId); + rsp->hdr.Status = STATUS_NETWORK_NAME_DELETED; smb2_set_err_rsp(work); return 0;