9p: use unsigned integers for nwqid/count
authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tue, 30 Dec 2014 00:48:09 +0000 (02:48 +0200)
committerEric Van Hensbergen <ericvh@gmail.com>
Fri, 20 Mar 2015 14:34:42 +0000 (07:34 -0700)
commit6250a8badb311953a49bedb16ed17eb59d21c03a
tree53432ea0f158736b5a1f839935098cfba577d2c4
parentb642f7269bd40ae9abe9cff01581b2eb5e2c2287
9p: use unsigned integers for nwqid/count

As specification says, all integers in messages are unsigned. Let's fix
behaviour of p9pdu_vreadf()/p9pdu_vwritef() accordingly.

Fix for p9pdu_vreadf() is critical. If server replies with Rwalk, where
nwqid > SHRT_MAX, the value will be interpreted as negative. kmalloc, in
its order, will cast the value to (very big) size_t.

It should never happen in normal situation: we never submit Twalk with
nwname > 16, but malicious or broken server can still produce
problematic Rwalk.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
net/9p/protocol.c