From: Pavel Shilovsky <piastryyy@gmail.com>
Date: Tue, 5 Mar 2019 15:51:55 -0800
Subject: [PATCH] CIFS: Only send SMB2_NEGOTIATE command on new TCP connections
Git-commit: 2084ed57167c3e39f99ac2bb19f19e85321d2169
Patch-mainline: v5.1-rc1
References: bsc#1144333
Do not allow commands other than SMB2_NEGOTIATE to be sent over
recently established TCP connections. Return -EAGAIN to let upper
layers handle it properly.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/smb2transport.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index fa1fec2e3c8d..d1181572758b 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -619,6 +619,10 @@ smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_sync_hdr *shdr,
return -EAGAIN;
}
+ if (ses->server->tcpStatus == CifsNeedNegotiate &&
+ shdr->Command != SMB2_NEGOTIATE)
+ return -EAGAIN;
+
if (ses->status == CifsNew) {
if ((shdr->Command != SMB2_SESSION_SETUP) &&
(shdr->Command != SMB2_NEGOTIATE))
@@ -702,6 +706,10 @@ smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
(struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
struct mid_q_entry *mid;
+ if (server->tcpStatus == CifsNeedNegotiate &&
+ shdr->Command != SMB2_NEGOTIATE)
+ return ERR_PTR(-EAGAIN);
+
smb2_seq_num_into_buf(server, shdr);
mid = smb2_mid_entry_alloc(shdr, server);
--
2.16.4