From: Namjae Jeon <linkinjeon@kernel.org>
To: linux-cifs@vger.kernel.org
Cc: "Namjae Jeon" <linkinjeon@kernel.org>,
"Ronnie Sahlberg" <ronniesahlberg@gmail.com>,
"Ralph Böhme" <slow@samba.org>,
"Steve French" <smfrench@gmail.com>,
"Ronnie Sahlberg" <lsahlber@redhat.com>
Subject: [PATCH 3/3] ksmbd: fix invalid request buffer access in compound request
Date: Tue, 21 Sep 2021 21:41:39 +0900 [thread overview]
Message-ID: <20210921124139.18312-3-linkinjeon@kernel.org> (raw)
In-Reply-To: <20210921124139.18312-1-linkinjeon@kernel.org>
Ronnie reported invalid request buffer access in chained command when
inserting garbage value to NextCommand of compound request.
This patch add validation check to avoid this issue.
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Ralph Böhme <slow@samba.org>
Cc: Steve French <smfrench@gmail.com>
Reported-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
fs/ksmbd/smb2pdu.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 1fe37ad4e5bc..cae796ea1148 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -466,6 +466,13 @@ bool is_chained_smb2_message(struct ksmbd_work *work)
hdr = ksmbd_req_buf_next(work);
if (le32_to_cpu(hdr->NextCommand) > 0) {
+ if (work->next_smb2_rcv_hdr_off + le32_to_cpu(hdr->NextCommand) >
+ get_rfc1002_len(work->request_buf)) {
+ pr_err("next command(%u) offset exceeds smb msg size\n",
+ hdr->NextCommand);
+ return false;
+ }
+
ksmbd_debug(SMB, "got SMB2 chained command\n");
init_chained_smb2_rsp(work);
return true;
--
2.25.1
prev parent reply other threads:[~2021-09-21 12:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-21 12:41 [PATCH 1/3] ksmbd: remove RFC1002 check in smb2 request Namjae Jeon
2021-09-21 12:41 ` [PATCH 2/3] ksmbd: add validation in smb2 negotiate Namjae Jeon
2021-09-21 12:41 ` Namjae Jeon [this message]
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