rpc: clean up decoding of gssproxy linux creds

We can use the normal coding infrastructure here.

Two minor behavior changes:

	- we're assuming no wasted space at the end of the linux cred.
	  That seems to match gss-proxy's behavior, and I can't see why
	  it would need to do differently in the future.

	- NGROUPS_MAX check added: note groups_alloc doesn't do this,
	  this is the caller's responsibility.

Tested-by: Simo Sorce <simo@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2013-08-21 10:32:52 -04:00
parent 11d2a1618e
commit 778e512bb1
1 changed files with 13 additions and 19 deletions

View File

@ -166,14 +166,14 @@ static int dummy_dec_opt_array(struct xdr_stream *xdr,
return 0;
}
static int get_s32(void **p, void *max, s32 *res)
static int get_s32(struct xdr_stream *xdr, s32 *res)
{
void *base = *p;
void *next = (void *)((char *)base + sizeof(s32));
if (unlikely(next > max || next < base))
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (!p)
return -EINVAL;
memcpy(res, base, sizeof(s32));
*p = next;
memcpy(res, p, sizeof(s32));
return 0;
}
@ -182,7 +182,6 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr,
{
u32 length;
__be32 *p;
void *q, *end;
s32 tmp;
int N, i, err;
@ -192,33 +191,28 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr,
length = be32_to_cpup(p);
/* FIXME: we do not want to use the scratch buffer for this one
* may need to use functions that allows us to access an io vector
* directly */
p = xdr_inline_decode(xdr, length);
if (unlikely(p == NULL))
if (length > (3 + NGROUPS_MAX) * sizeof(u32))
return -ENOSPC;
q = p;
end = q + length;
/* uid */
err = get_s32(&q, end, &tmp);
err = get_s32(xdr, &tmp);
if (err)
return err;
creds->cr_uid = make_kuid(&init_user_ns, tmp);
/* gid */
err = get_s32(&q, end, &tmp);
err = get_s32(xdr, &tmp);
if (err)
return err;
creds->cr_gid = make_kgid(&init_user_ns, tmp);
/* number of additional gid's */
err = get_s32(&q, end, &tmp);
err = get_s32(xdr, &tmp);
if (err)
return err;
N = tmp;
if ((3 + N) * sizeof(u32) != length)
return -EINVAL;
creds->cr_group_info = groups_alloc(N);
if (creds->cr_group_info == NULL)
return -ENOMEM;
@ -226,7 +220,7 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr,
/* gid's */
for (i = 0; i < N; i++) {
kgid_t kgid;
err = get_s32(&q, end, &tmp);
err = get_s32(xdr, &tmp);
if (err)
goto out_free_groups;
err = -EINVAL;