tree 9cc6df10ac849488efe28ea811e55c213c22a754
parent 10bd295a0b6488ebe634b72a11d8986bd3af3819
author Sachin Prabhu <sprabhu@redhat.com> 1334669739 +0100
committer Trond Myklebust <Trond.Myklebust@netapp.com> 1335546907 -0400

Avoid reading past buffer when calling GETACL

Bug noticed in commit
bf118a342f10dafe44b14451a1392c3254629a1f

When calling GETACL, if the size of the bitmap array, the length
attribute and the acl returned by the server is greater than the
allocated buffer(args.acl_len), we can Oops with a General Protection
fault at _copy_from_pages() when we attempt to read past the pages
allocated.

This patch allocates an extra PAGE for the bitmap and checks to see that
the bitmap + attribute_length + ACLs don't exceed the buffer space
allocated to it.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: Jian Li <jiali@redhat.com>
[Trond: Fixed a size_t vs unsigned int printk() warning]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>