All of lore.kernel.org
 help / color / mirror / Atom feed
From: Namjae Jeon <linkinjeon@kernel.org>
To: linux-cifs@vger.kernel.org
Cc: "Namjae Jeon" <linkinjeon@kernel.org>,
	"Tom Talpey" <tom@talpey.com>,
	"Ronnie Sahlberg" <ronniesahlberg@gmail.com>,
	"Ralph Böhme" <slow@samba.org>,
	"Steve French" <smfrench@gmail.com>,
	"Hyunchul Lee" <hyc.lee@gmail.com>,
	"Sergey Senozhatsky" <senozhatsky@chromium.org>
Subject: [PATCH 6/7] ksmbd: fix invalid request buffer access in compound
Date: Fri, 24 Sep 2021 11:12:53 +0900	[thread overview]
Message-ID: <20210924021254.27096-7-linkinjeon@kernel.org> (raw)
In-Reply-To: <20210924021254.27096-1-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: Tom Talpey <tom@talpey.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Ralph Böhme <slow@samba.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/smb2pdu.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index a930838fd6ac..4f7b5e18a7b9 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -459,13 +459,22 @@ static void init_chained_smb2_rsp(struct ksmbd_work *work)
 bool is_chained_smb2_message(struct ksmbd_work *work)
 {
 	struct smb2_hdr *hdr = work->request_buf;
-	unsigned int len;
+	unsigned int len, next_cmd;
 
 	if (hdr->ProtocolId != SMB2_PROTO_NUMBER)
 		return false;
 
 	hdr = ksmbd_req_buf_next(work);
-	if (le32_to_cpu(hdr->NextCommand) > 0) {
+	next_cmd = le32_to_cpu(hdr->NextCommand);
+	if (next_cmd > 0) {
+		if ((u64)work->next_smb2_rcv_hdr_off + next_cmd +
+			__SMB2_HEADER_STRUCTURE_SIZE >
+		    get_rfc1002_len(work->request_buf)) {
+			pr_err("next command(%u) offset exceeds smb msg size\n",
+			       next_cmd);
+			return false;
+		}
+
 		ksmbd_debug(SMB, "got SMB2 chained command\n");
 		init_chained_smb2_rsp(work);
 		return true;
-- 
2.25.1


  parent reply	other threads:[~2021-09-24  2:13 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24  2:12 [PATCH 0/7] a bunch of patches that have not yet been reviewed Namjae Jeon
2021-09-24  2:12 ` [PATCH 1/7] ksmbd: add validation in smb2_ioctl Namjae Jeon
2021-09-25 10:16   ` Hyunchul Lee
2021-09-25 10:44     ` Namjae Jeon
2021-09-24  2:12 ` [PATCH 2/7] ksmbd: add request buffer validation in smb2_set_info Namjae Jeon
2021-09-25  8:13   ` Hyunchul Lee
2021-09-25  9:19     ` Namjae Jeon
2021-09-24  2:12 ` [PATCH 3/7] ksmbd: remove RFC1002 check in smb2 request Namjae Jeon
2021-09-25  8:18   ` Hyunchul Lee
2021-09-24  2:12 ` [PATCH 4/7] ksmbd: check strictly data area in ksmbd_smb2_check_message() Namjae Jeon
2021-09-25 10:27   ` Hyunchul Lee
2021-09-25 10:46     ` Namjae Jeon
2021-09-24  2:12 ` [PATCH 5/7] ksmbd: add the check to vaildate if stream protocol length exceeds maximum value Namjae Jeon
2021-09-25  8:41   ` Hyunchul Lee
2021-09-25  9:24     ` Namjae Jeon
2021-09-24  2:12 ` Namjae Jeon [this message]
2021-09-25  9:41   ` [PATCH 6/7] ksmbd: fix invalid request buffer access in compound Hyunchul Lee
2021-09-24  2:12 ` [PATCH 7/7] ksmbd: add validation in smb2 negotiate Namjae Jeon
2021-09-24  4:58   ` Namjae Jeon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210924021254.27096-7-linkinjeon@kernel.org \
    --to=linkinjeon@kernel.org \
    --cc=hyc.lee@gmail.com \
    --cc=linux-cifs@vger.kernel.org \
    --cc=ronniesahlberg@gmail.com \
    --cc=senozhatsky@chromium.org \
    --cc=slow@samba.org \
    --cc=smfrench@gmail.com \
    --cc=tom@talpey.com \
    --subject='Re: [PATCH 6/7] ksmbd: fix invalid request buffer access in compound' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.