Avoid reading past buffer when calling GETACL
commit22594eea7aea374c0680f70fd89eeb1fc47ae635
authorSachin Prabhu <sprabhu@redhat.com>
Tue, 17 Apr 2012 13:35:39 +0000 (17 14:35 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 21 May 2012 17:46:24 +0000 (21 10:46 -0700)
treefde98636153ccdd7539e03ccb2758c5902376c9d
parent4262cd1f4b734ea5fa05c37043c89106f38b2daa
Avoid reading past buffer when calling GETACL

commit 5a00689930ab975fdd1b37b034475017e460cf2a upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/nfs/nfs4proc.c
fs/nfs/nfs4xdr.c