From: Jordy Zomer <jordyzomer@google.com>
Date: Thu, 28 Nov 2024 00:33:25 +0000 (+0900)
Subject: ksmbd: fix Out-of-Bounds Write in ksmbd_vfs_stream_write
X-Git-Tag: v6.12.5~341
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5797f195c67132d061d29c57a7c6d30530686f0;p=thirdparty%2Fkernel%2Fstable.git

ksmbd: fix Out-of-Bounds Write in ksmbd_vfs_stream_write

commit 313dab082289e460391c82d855430ec8a28ddf81 upstream.

An offset from client could be a negative value, It could allows
to write data outside the bounds of the allocated buffer.
Note that this issue is coming when setting
'vfs objects = streams_xattr parameter' in ksmbd.conf.

Cc: stable@vger.kernel.org # v5.15+
Reported-by: Jordy Zomer <jordyzomer@google.com>
Signed-off-by: Jordy Zomer <jordyzomer@google.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index ce6dff5c7d741..d0836d710f181 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -6868,6 +6868,8 @@ int smb2_write(struct ksmbd_work *work)
 	}
 
 	offset = le64_to_cpu(req->Offset);
+	if (offset < 0)
+		return -EINVAL;
 	length = le32_to_cpu(req->Length);
 
 	if (req->Channel == SMB2_CHANNEL_RDMA_V1 ||