tree c69044602bbfae2ccc16001ee0fab8b8752dba95
parent e16453a31a00c1c0a199cab0617e8aa888f6419a
author Christian Schoenebeck <qemu_oss@crudebyte.com> 1581150259 +0100
committer Greg Kurz <groug@kaod.org> 1581150534 +0100

9pfs: validate count sent by client with T_readdir

A good 9p client sends T_readdir with "count" parameter that's sufficiently
smaller than client's initially negotiated msize (maximum message size).
We perform a check for that though to avoid the server to be interrupted
with a "Failed to encode VirtFS reply type 41" transport error message by
bad clients. This count value constraint uses msize - 11, because 11 is the
header size of R_readdir.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <3990d3891e8ae2074709b56449e96ab4b4b93b7d.1579567020.git.qemu_oss@crudebyte.com>
[groug: added comment ]
Signed-off-by: Greg Kurz <groug@kaod.org>