From 78f1688a64cca77758ceb9b183088cf0054bfc82 Mon Sep 17 00:00:00 2001 From: Marios Makassikis Date: Thu, 28 Oct 2021 21:01:27 +0200 Subject: [PATCH] ksmbd: Fix buffer length check in fsctl_validate_negotiate_info() The validate_negotiate_info_req struct definition includes an extra field to access the data coming after the header. This causes the check in fsctl_validate_negotiate_info() to count the first element of the array twice. This in turn makes some valid requests fail, depending on whether they include padding or not. Fixes: f7db8fd03a4b ("ksmbd: add validation in smb2_ioctl") Cc: stable@vger.kernel.org # v5.15 Acked-by: Namjae Jeon Acked-by: Hyunchul Lee Signed-off-by: Marios Makassikis Signed-off-by: Steve French --- fs/ksmbd/smb2pdu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index eb23c44..a925e0f 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -7313,7 +7313,7 @@ static int fsctl_validate_negotiate_info(struct ksmbd_conn *conn, int ret = 0; int dialect; - if (in_buf_len < sizeof(struct validate_negotiate_info_req) + + if (in_buf_len < offsetof(struct validate_negotiate_info_req, Dialects) + le16_to_cpu(neg_req->DialectCount) * sizeof(__le16)) return -EINVAL; -- 2.7.4