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From: Namjae Jeon <linkinjeon@kernel.org>
To: linux-cifs@vger.kernel.org
Cc: Namjae Jeon <linkinjeon@kernel.org>
Subject: [PATCH] ksmbd: fix potencial 32bit overflow from data area check in smb2_write
Date: Tue, 12 Oct 2021 10:20:04 +0900	[thread overview]
Message-ID: <20211012012006.5037-1-linkinjeon@kernel.org> (raw)

DataOffset and Length validation can be potencial 32bit overflow.
This patch fix it.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/smb2pdu.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 79b296abe04e..7b4689f2df49 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -6197,8 +6197,7 @@ static noinline int smb2_write_pipe(struct ksmbd_work *work)
 	    (offsetof(struct smb2_write_req, Buffer) - 4)) {
 		data_buf = (char *)&req->Buffer[0];
 	} else {
-		if ((le16_to_cpu(req->DataOffset) > get_rfc1002_len(req)) ||
-		    (le16_to_cpu(req->DataOffset) + length > get_rfc1002_len(req))) {
+		if ((u64)le16_to_cpu(req->DataOffset) + length > get_rfc1002_len(req)) {
 			pr_err("invalid write data offset %u, smb_len %u\n",
 			       le16_to_cpu(req->DataOffset),
 			       get_rfc1002_len(req));
@@ -6356,8 +6355,7 @@ int smb2_write(struct ksmbd_work *work)
 		    (offsetof(struct smb2_write_req, Buffer) - 4)) {
 			data_buf = (char *)&req->Buffer[0];
 		} else {
-			if ((le16_to_cpu(req->DataOffset) > get_rfc1002_len(req)) ||
-			    (le16_to_cpu(req->DataOffset) + length > get_rfc1002_len(req))) {
+			if ((u64)le16_to_cpu(req->DataOffset) + length > get_rfc1002_len(req)) {
 				pr_err("invalid write data offset %u, smb_len %u\n",
 				       le16_to_cpu(req->DataOffset),
 				       get_rfc1002_len(req));
-- 
2.25.1


             reply	other threads:[~2021-10-12  1:20 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-12  1:20 Namjae Jeon [this message]
2021-10-12  1:20 ` [PATCH] ksmbd: validate compound response buffer Namjae Jeon

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