cifs: Fix potential OOB access of lock element array

If maxBuf is small but non-zero, it could result in a zero sized lock
element array which we would then try and access OOB.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
This commit is contained in:
Ross Lagerwall
2019-01-08 18:30:57 +00:00
committed by Steve French
szülő 92a8109e4d
commit b9a74cde94
2 fájl változott, egészen pontosan 6 új sor hozzáadva és 6 régi sor törölve

Fájl megtekintése

@@ -1132,10 +1132,10 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
/*
* Accessing maxBuf is racy with cifs_reconnect - need to store value
* and check it for zero before using.
* and check it before using.
*/
max_buf = tcon->ses->server->maxBuf;
if (!max_buf) {
if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) {
free_xid(xid);
return -EINVAL;
}
@@ -1476,10 +1476,10 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
/*
* Accessing maxBuf is racy with cifs_reconnect - need to store value
* and check it for zero before using.
* and check it before using.
*/
max_buf = tcon->ses->server->maxBuf;
if (!max_buf)
if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE)))
return -EINVAL;
BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >