ksmbd: validate smb request protocol id

This patch add the validation for smb request protocol id.
If it is not one of the four ids(SMB1_PROTO_NUMBER, SMB2_PROTO_NUMBER,
SMB2_TRANSFORM_PROTO_NUM, SMB2_COMPRESSION_TRANSFORM_ID), don't allow
processing the request. And this will fix the following KASAN warning
also.

[   13.905265] BUG: KASAN: slab-out-of-bounds in init_smb2_rsp_hdr+0x1b9/0x1f0
[   13.905900] Read of size 16 at addr ffff888005fd2f34 by task kworker/0:2/44
...
[   13.908553] Call Trace:
[   13.908793]  <TASK>
[   13.908995]  dump_stack_lvl+0x33/0x50
[   13.909369]  print_report+0xcc/0x620
[   13.910870]  kasan_report+0xae/0xe0
[   13.911519]  kasan_check_range+0x35/0x1b0
[   13.911796]  init_smb2_rsp_hdr+0x1b9/0x1f0
[   13.912492]  handle_ksmbd_work+0xe5/0x820

Cc: stable@vger.kernel.org
Reported-by: Chih-Yen Chang <cc85nod@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Namjae Jeon 2023-05-31 17:59:32 +09:00 committed by Steve French
parent 368ba06881
commit 1c1bcf2d3e
2 changed files with 16 additions and 3 deletions

View file

@ -364,8 +364,6 @@ int ksmbd_conn_handler_loop(void *p)
break;
memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
if (!ksmbd_smb_request(conn))
break;
/*
* We already read 4 bytes to find out PDU size, now
@ -383,6 +381,9 @@ int ksmbd_conn_handler_loop(void *p)
continue;
}
if (!ksmbd_smb_request(conn))
break;
if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
SMB2_PROTO_NUMBER) {
if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)

View file

@ -158,7 +158,19 @@ int ksmbd_verify_smb_message(struct ksmbd_work *work)
*/
bool ksmbd_smb_request(struct ksmbd_conn *conn)
{
return conn->request_buf[0] == 0;
__le32 *proto = (__le32 *)smb2_get_msg(conn->request_buf);
if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) {
pr_err_ratelimited("smb2 compression not support yet");
return false;
}
if (*proto != SMB1_PROTO_NUMBER &&
*proto != SMB2_PROTO_NUMBER &&
*proto != SMB2_TRANSFORM_PROTO_NUM)
return false;
return true;
}
static bool supported_protocol(int idx)