On Wed, Feb 13, 2013 at 09:51:38AM -0800, Eric W. Biederman wrote:
> From: "Eric W. Biederman" <ebied...@xmission.com>
> 
> For each received uid call make_kuid and validate the result.
> For each received gid call make_kgid and validate the result.
> 
> Cc: "J. Bruce Fields" <bfie...@fieldses.org>
> Cc: Trond Myklebust <trond.mykleb...@netapp.com>
> Signed-off-by: "Eric W. Biederman" <ebied...@xmission.com>
> ---
>  net/sunrpc/auth_gss/svcauth_gss.c |   18 +++++++++++++-----
>  1 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/net/sunrpc/auth_gss/svcauth_gss.c 
> b/net/sunrpc/auth_gss/svcauth_gss.c
> index 73e9573..ecd1d58 100644
> --- a/net/sunrpc/auth_gss/svcauth_gss.c
> +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> @@ -418,6 +418,7 @@ static int rsc_parse(struct cache_detail *cd,
>  {
>       /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] 
> */
>       char *buf = mesg;
> +     int id;
>       int len, rv;
>       struct rsc rsci, *rscp = NULL;
>       time_t expiry;
> @@ -444,7 +445,7 @@ static int rsc_parse(struct cache_detail *cd,
>               goto out;
>  
>       /* uid, or NEGATIVE */
> -     rv = get_int(&mesg, &rsci.cred.cr_uid);
> +     rv = get_int(&mesg, &id);
>       if (rv == -EINVAL)
>               goto out;
>       if (rv == -ENOENT)
> @@ -452,8 +453,16 @@ static int rsc_parse(struct cache_detail *cd,
>       else {
>               int N, i;
>  
> +             /* uid */
> +             rsci.cred.cr_uid = make_kuid(&init_user_ns, id);
> +             if (!uid_valid(rsci.cred.cr_uid))
> +                     goto out;
> +
>               /* gid */
> -             if (get_int(&mesg, &rsci.cred.cr_gid))
> +             if (get_int(&mesg, &id))
> +                     goto out;
> +             rsci.cred.cr_gid = make_kgid(&init_user_ns, id);
> +             if (!gid_valid(rsci.cred.cr_gid))
>                       goto out;

krb5 mounts started failing for me as of this patch (upstream as
683428fae8c73d7d7da0fa2e0b6beb4d8df4e808), and I believe the problem is
these uid/gid_valid checks: if I recall correctly, gssd uses -1 uid/gid
values to indicate "authentication succeeded, but treat this user as
anonymous".  We delay mapping -1 id's to the (configurable-per-export)
anonymous id's till fs/nfsd/auth.c:nfsd_setuser():

        if (uid_eq(new->fsuid, INVALID_UID))
                new->fsuid = exp->ex_anon_uid;
        if (gid_eq(new->fsgid, INVALID_GID))
                new->fsgid = exp->ex_anon_gid;

(We wouldn't be able to do that earlier because we don't know the export
yet.)

Confirmed that the following fixes the regression.

Eric, any objection to removing those checks?

--b.

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c 
b/net/sunrpc/auth_gss/svcauth_gss.c
index f7d34e7..59a089d 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -449,15 +449,11 @@ static int rsc_parse(struct cache_detail *cd,
 
                /* uid */
                rsci.cred.cr_uid = make_kuid(&init_user_ns, id);
-               if (!uid_valid(rsci.cred.cr_uid))
-                       goto out;
 
                /* gid */
                if (get_int(&mesg, &id))
                        goto out;
                rsci.cred.cr_gid = make_kgid(&init_user_ns, id);
-               if (!gid_valid(rsci.cred.cr_gid))
-                       goto out;
 
                /* number of additional gid's */
                if (get_int(&mesg, &N))
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to