From: Jordy Zomer <jordyzomer@google.com>
Date: Thu, 28 Nov 2024 00:32:45 +0000 (+0900)
Subject: ksmbd: fix Out-of-Bounds Read in ksmbd_vfs_stream_read
X-Git-Tag: v5.15.176~76
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6bd1bf0e8c42f10a9a9679a4c103a9032d30594d;p=thirdparty%2Fkernel%2Fstable.git

ksmbd: fix Out-of-Bounds Read in ksmbd_vfs_stream_read

[ Upstream commit fc342cf86e2dc4d2edb0fc2ff5e28b6c7845adb9 ]

An offset from client could be a negative value, It could lead
to an out-of-bounds read from the stream_buf.
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: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 54f7cf7a98b2b..35914c9809aa9 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -6350,6 +6350,10 @@ int smb2_read(struct ksmbd_work *work)
 	}
 
 	offset = le64_to_cpu(req->Offset);
+	if (offset < 0) {
+		err = -EINVAL;
+		goto out;
+	}
 	length = le32_to_cpu(req->Length);
 	mincount = le32_to_cpu(req->MinimumCount);