linux/net/sunrpc/auth_gss/gss_krb5_mech.c
Trond Myklebust 14ace024b1 SUNRPC: Fix up an error return value in gss_import_sec_context_kerberos()
If the context allocation fails, the function currently returns a random
error code, since the variable 'p' still points to a valid memory location.

Ensure that it returns ENOMEM...

Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-12-18 16:28:05 -05:00

264 lines
7.1 KiB
C

/*
* linux/net/sunrpc/gss_krb5_mech.c
*
* Copyright (c) 2001 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@umich.edu>
* J. Bruce Fields <bfields@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/sunrpc/xdr.h>
#include <linux/crypto.h>
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static const void *
simple_get_bytes(const void *p, const void *end, void *res, int len)
{
const void *q = (const void *)((const char *)p + len);
if (unlikely(q > end || q < p))
return ERR_PTR(-EFAULT);
memcpy(res, p, len);
return q;
}
static const void *
simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
{
const void *q;
unsigned int len;
p = simple_get_bytes(p, end, &len, sizeof(len));
if (IS_ERR(p))
return p;
q = (const void *)((const char *)p + len);
if (unlikely(q > end || q < p))
return ERR_PTR(-EFAULT);
res->data = kmemdup(p, len, GFP_NOFS);
if (unlikely(res->data == NULL))
return ERR_PTR(-ENOMEM);
res->len = len;
return q;
}
static inline const void *
get_key(const void *p, const void *end, struct crypto_blkcipher **res)
{
struct xdr_netobj key;
int alg;
char *alg_name;
p = simple_get_bytes(p, end, &alg, sizeof(alg));
if (IS_ERR(p))
goto out_err;
p = simple_get_netobj(p, end, &key);
if (IS_ERR(p))
goto out_err;
switch (alg) {
case ENCTYPE_DES_CBC_RAW:
alg_name = "cbc(des)";
break;
default:
printk("gss_kerberos_mech: unsupported algorithm %d\n", alg);
goto out_err_free_key;
}
*res = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(*res)) {
printk("gss_kerberos_mech: unable to initialize crypto algorithm %s\n", alg_name);
*res = NULL;
goto out_err_free_key;
}
if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
printk("gss_kerberos_mech: error setting key for crypto algorithm %s\n", alg_name);
goto out_err_free_tfm;
}
kfree(key.data);
return p;
out_err_free_tfm:
crypto_free_blkcipher(*res);
out_err_free_key:
kfree(key.data);
p = ERR_PTR(-EINVAL);
out_err:
return p;
}
static int
gss_import_sec_context_kerberos(const void *p,
size_t len,
struct gss_ctx *ctx_id)
{
const void *end = (const void *)((const char *)p + len);
struct krb5_ctx *ctx;
int tmp;
if (!(ctx = kzalloc(sizeof(*ctx), GFP_NOFS))) {
p = ERR_PTR(-ENOMEM);
goto out_err;
}
p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
if (IS_ERR(p))
goto out_err_free_ctx;
/* The downcall format was designed before we completely understood
* the uses of the context fields; so it includes some stuff we
* just give some minimal sanity-checking, and some we ignore
* completely (like the next twenty bytes): */
if (unlikely(p + 20 > end || p + 20 < p))
goto out_err_free_ctx;
p += 20;
p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
if (IS_ERR(p))
goto out_err_free_ctx;
if (tmp != SGN_ALG_DES_MAC_MD5) {
p = ERR_PTR(-ENOSYS);
goto out_err_free_ctx;
}
p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
if (IS_ERR(p))
goto out_err_free_ctx;
if (tmp != SEAL_ALG_DES) {
p = ERR_PTR(-ENOSYS);
goto out_err_free_ctx;
}
p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
if (IS_ERR(p))
goto out_err_free_ctx;
p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
if (IS_ERR(p))
goto out_err_free_ctx;
p = simple_get_netobj(p, end, &ctx->mech_used);
if (IS_ERR(p))
goto out_err_free_ctx;
p = get_key(p, end, &ctx->enc);
if (IS_ERR(p))
goto out_err_free_mech;
p = get_key(p, end, &ctx->seq);
if (IS_ERR(p))
goto out_err_free_key1;
if (p != end) {
p = ERR_PTR(-EFAULT);
goto out_err_free_key2;
}
ctx_id->internal_ctx_id = ctx;
dprintk("RPC: Successfully imported new context.\n");
return 0;
out_err_free_key2:
crypto_free_blkcipher(ctx->seq);
out_err_free_key1:
crypto_free_blkcipher(ctx->enc);
out_err_free_mech:
kfree(ctx->mech_used.data);
out_err_free_ctx:
kfree(ctx);
out_err:
return PTR_ERR(p);
}
static void
gss_delete_sec_context_kerberos(void *internal_ctx) {
struct krb5_ctx *kctx = internal_ctx;
crypto_free_blkcipher(kctx->seq);
crypto_free_blkcipher(kctx->enc);
kfree(kctx->mech_used.data);
kfree(kctx);
}
static const struct gss_api_ops gss_kerberos_ops = {
.gss_import_sec_context = gss_import_sec_context_kerberos,
.gss_get_mic = gss_get_mic_kerberos,
.gss_verify_mic = gss_verify_mic_kerberos,
.gss_wrap = gss_wrap_kerberos,
.gss_unwrap = gss_unwrap_kerberos,
.gss_delete_sec_context = gss_delete_sec_context_kerberos,
};
static struct pf_desc gss_kerberos_pfs[] = {
[0] = {
.pseudoflavor = RPC_AUTH_GSS_KRB5,
.service = RPC_GSS_SVC_NONE,
.name = "krb5",
},
[1] = {
.pseudoflavor = RPC_AUTH_GSS_KRB5I,
.service = RPC_GSS_SVC_INTEGRITY,
.name = "krb5i",
},
[2] = {
.pseudoflavor = RPC_AUTH_GSS_KRB5P,
.service = RPC_GSS_SVC_PRIVACY,
.name = "krb5p",
},
};
static struct gss_api_mech gss_kerberos_mech = {
.gm_name = "krb5",
.gm_owner = THIS_MODULE,
.gm_oid = {9, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02"},
.gm_ops = &gss_kerberos_ops,
.gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
.gm_pfs = gss_kerberos_pfs,
};
static int __init init_kerberos_module(void)
{
int status;
status = gss_mech_register(&gss_kerberos_mech);
if (status)
printk("Failed to register kerberos gss mechanism!\n");
return status;
}
static void __exit cleanup_kerberos_module(void)
{
gss_mech_unregister(&gss_kerberos_mech);
}
MODULE_LICENSE("GPL");
module_init(init_kerberos_module);
module_exit(cleanup_kerberos_module);