smb3: Handle error case during offload read path

commit 1254100030b3377e8302f9c75090ab191d73ee7c upstream.

Mid callback needs to be called only when valid data is
read into pages.

These patches address a problem found during decryption offload:
      CIFS: VFS: trying to dequeue a deleted mid
that could cause a refcount use after free:
      Workqueue: smb3decryptd smb2_decrypt_offload [cifs]

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> #5.4+
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Rohith Surabattula 2020-10-29 06:07:56 +00:00 committed by Greg Kroah-Hartman
parent afa51221b9
commit 56f639aa0b

View File

@ -4183,7 +4183,25 @@ static void smb2_decrypt_offload(struct work_struct *work)
dw->server->vals->read_rsp_size,
dw->ppages, dw->npages, dw->len,
true);
mid->callback(mid);
if (rc >= 0) {
#ifdef CONFIG_CIFS_STATS2
mid->when_received = jiffies;
#endif
mid->callback(mid);
} else {
spin_lock(&GlobalMid_Lock);
if (dw->server->tcpStatus == CifsNeedReconnect) {
mid->mid_state = MID_RETRY_NEEDED;
spin_unlock(&GlobalMid_Lock);
mid->callback(mid);
} else {
mid->mid_state = MID_REQUEST_SUBMITTED;
mid->mid_flags &= ~(MID_DELETED);
list_add_tail(&mid->qhead,
&dw->server->pending_mid_q);
spin_unlock(&GlobalMid_Lock);
}
}
cifs_mid_q_entry_release(mid);
}