tree 4718cdc2e494f18ab13c2c8f09930953b77c31ff
parent 21f498c2f73bd6150d82931f09965826dca0b5f2
author Trond Myklebust <Trond.Myklebust@netapp.com> 1346006683 -0700
committer Trond Myklebust <Trond.Myklebust@netapp.com> 1346944313 -0400

NFSv4: Fix buffer overflow checking in __nfs4_get_acl_uncached

Pass the checks made by decode_getacl back to __nfs4_get_acl_uncached
so that it knows if the acl has been truncated.

The current overflow checking is broken, resulting in Oopses on
user-triggered nfs4_getfacl calls, and is opaque to the point
where several attempts at fixing it have failed.
This patch tries to clean up the code in addition to fixing the
Oopses by ensuring that the overflow checks are performed in
a single place (decode_getacl). If the overflow check failed,
we will still be able to report the acl length, but at least
we will no longer attempt to cache the acl or copy the
truncated contents to user space.

Reported-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Sachin Prabhu <sprabhu@redhat.com>