linux/net/sunrpc/auth_gss/gss_mech_switch.c
NeilBrown 24c5efe41c sunrpc: clean up properly in gss_mech_unregister()
gss_mech_register() calls svcauth_gss_register_pseudoflavor() for each
flavour, but gss_mech_unregister() does not call auth_domain_put().
This is unbalanced and makes it impossible to reload the module.

Change svcauth_gss_register_pseudoflavor() to return the registered
auth_domain, and save it for later release.

Cc: stable@vger.kernel.org (v2.6.12+)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-05-28 18:15:00 -04:00

449 lines
10 KiB
C

// SPDX-License-Identifier: BSD-3-Clause
/*
* linux/net/sunrpc/gss_mech_switch.c
*
* Copyright (c) 2001 The Regents of the University of Michigan.
* All rights reserved.
*
* J. Bruce Fields <bfields@umich.edu>
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/oid_registry.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/gss_asn1.h>
#include <linux/sunrpc/auth_gss.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/gss_err.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/gss_api.h>
#include <linux/sunrpc/clnt.h>
#include <trace/events/rpcgss.h>
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static LIST_HEAD(registered_mechs);
static DEFINE_SPINLOCK(registered_mechs_lock);
static void
gss_mech_free(struct gss_api_mech *gm)
{
struct pf_desc *pf;
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
pf = &gm->gm_pfs[i];
if (pf->domain)
auth_domain_put(pf->domain);
kfree(pf->auth_domain_name);
pf->auth_domain_name = NULL;
}
}
static inline char *
make_auth_domain_name(char *name)
{
static char *prefix = "gss/";
char *new;
new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
if (new) {
strcpy(new, prefix);
strcat(new, name);
}
return new;
}
static int
gss_mech_svc_setup(struct gss_api_mech *gm)
{
struct auth_domain *dom;
struct pf_desc *pf;
int i, status;
for (i = 0; i < gm->gm_pf_num; i++) {
pf = &gm->gm_pfs[i];
pf->auth_domain_name = make_auth_domain_name(pf->name);
status = -ENOMEM;
if (pf->auth_domain_name == NULL)
goto out;
dom = svcauth_gss_register_pseudoflavor(
pf->pseudoflavor, pf->auth_domain_name);
if (IS_ERR(dom)) {
status = PTR_ERR(dom);
goto out;
}
pf->domain = dom;
}
return 0;
out:
gss_mech_free(gm);
return status;
}
/**
* gss_mech_register - register a GSS mechanism
* @gm: GSS mechanism handle
*
* Returns zero if successful, or a negative errno.
*/
int gss_mech_register(struct gss_api_mech *gm)
{
int status;
status = gss_mech_svc_setup(gm);
if (status)
return status;
spin_lock(&registered_mechs_lock);
list_add_rcu(&gm->gm_list, &registered_mechs);
spin_unlock(&registered_mechs_lock);
dprintk("RPC: registered gss mechanism %s\n", gm->gm_name);
return 0;
}
EXPORT_SYMBOL_GPL(gss_mech_register);
/**
* gss_mech_unregister - release a GSS mechanism
* @gm: GSS mechanism handle
*
*/
void gss_mech_unregister(struct gss_api_mech *gm)
{
spin_lock(&registered_mechs_lock);
list_del_rcu(&gm->gm_list);
spin_unlock(&registered_mechs_lock);
dprintk("RPC: unregistered gss mechanism %s\n", gm->gm_name);
gss_mech_free(gm);
}
EXPORT_SYMBOL_GPL(gss_mech_unregister);
struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
{
__module_get(gm->gm_owner);
return gm;
}
EXPORT_SYMBOL(gss_mech_get);
static struct gss_api_mech *
_gss_mech_get_by_name(const char *name)
{
struct gss_api_mech *pos, *gm = NULL;
rcu_read_lock();
list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
if (0 == strcmp(name, pos->gm_name)) {
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
}
rcu_read_unlock();
return gm;
}
struct gss_api_mech * gss_mech_get_by_name(const char *name)
{
struct gss_api_mech *gm = NULL;
gm = _gss_mech_get_by_name(name);
if (!gm) {
request_module("rpc-auth-gss-%s", name);
gm = _gss_mech_get_by_name(name);
}
return gm;
}
struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
{
struct gss_api_mech *pos, *gm = NULL;
char buf[32];
if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
return NULL;
request_module("rpc-auth-gss-%s", buf);
rcu_read_lock();
list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
if (obj->len == pos->gm_oid.len) {
if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
}
}
rcu_read_unlock();
if (!gm)
trace_rpcgss_oid_to_mech(buf);
return gm;
}
static inline int
mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
return 1;
}
return 0;
}
static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
{
struct gss_api_mech *gm = NULL, *pos;
rcu_read_lock();
list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
if (!mech_supports_pseudoflavor(pos, pseudoflavor))
continue;
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
rcu_read_unlock();
return gm;
}
struct gss_api_mech *
gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
{
struct gss_api_mech *gm;
gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
if (!gm) {
request_module("rpc-auth-gss-%u", pseudoflavor);
gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
}
return gm;
}
/**
* gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
* @gm: GSS mechanism handle
* @qop: GSS quality-of-protection value
* @service: GSS service value
*
* Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
*/
rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
u32 service)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].qop == qop &&
gm->gm_pfs[i].service == service) {
return gm->gm_pfs[i].pseudoflavor;
}
}
return RPC_AUTH_MAXFLAVOR;
}
/**
* gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
* @info: a GSS mech OID, quality of protection, and service value
*
* Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
* not supported.
*/
rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
{
rpc_authflavor_t pseudoflavor;
struct gss_api_mech *gm;
gm = gss_mech_get_by_OID(&info->oid);
if (gm == NULL)
return RPC_AUTH_MAXFLAVOR;
pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
gss_mech_put(gm);
return pseudoflavor;
}
/**
* gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
* @pseudoflavor: GSS pseudoflavor to match
* @info: rpcsec_gss_info structure to fill in
*
* Returns zero and fills in "info" if pseudoflavor matches a
* supported mechanism. Otherwise a negative errno is returned.
*/
int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
struct rpcsec_gss_info *info)
{
struct gss_api_mech *gm;
int i;
gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
if (gm == NULL)
return -ENOENT;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
info->oid.len = gm->gm_oid.len;
info->qop = gm->gm_pfs[i].qop;
info->service = gm->gm_pfs[i].service;
gss_mech_put(gm);
return 0;
}
}
gss_mech_put(gm);
return -ENOENT;
}
u32
gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
return gm->gm_pfs[i].service;
}
return 0;
}
EXPORT_SYMBOL(gss_pseudoflavor_to_service);
bool
gss_pseudoflavor_to_datatouch(struct gss_api_mech *gm, u32 pseudoflavor)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
return gm->gm_pfs[i].datatouch;
}
return false;
}
char *
gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].service == service)
return gm->gm_pfs[i].auth_domain_name;
}
return NULL;
}
void
gss_mech_put(struct gss_api_mech * gm)
{
if (gm)
module_put(gm->gm_owner);
}
EXPORT_SYMBOL(gss_mech_put);
/* The mech could probably be determined from the token instead, but it's just
* as easy for now to pass it in. */
int
gss_import_sec_context(const void *input_token, size_t bufsize,
struct gss_api_mech *mech,
struct gss_ctx **ctx_id,
time64_t *endtime,
gfp_t gfp_mask)
{
if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
return -ENOMEM;
(*ctx_id)->mech_type = gss_mech_get(mech);
return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
*ctx_id, endtime, gfp_mask);
}
/* gss_get_mic: compute a mic over message and return mic_token. */
u32
gss_get_mic(struct gss_ctx *context_handle,
struct xdr_buf *message,
struct xdr_netobj *mic_token)
{
return context_handle->mech_type->gm_ops
->gss_get_mic(context_handle,
message,
mic_token);
}
/* gss_verify_mic: check whether the provided mic_token verifies message. */
u32
gss_verify_mic(struct gss_ctx *context_handle,
struct xdr_buf *message,
struct xdr_netobj *mic_token)
{
return context_handle->mech_type->gm_ops
->gss_verify_mic(context_handle,
message,
mic_token);
}
/*
* This function is called from both the client and server code.
* Each makes guarantees about how much "slack" space is available
* for the underlying function in "buf"'s head and tail while
* performing the wrap.
*
* The client and server code allocate RPC_MAX_AUTH_SIZE extra
* space in both the head and tail which is available for use by
* the wrap function.
*
* Underlying functions should verify they do not use more than
* RPC_MAX_AUTH_SIZE of extra space in either the head or tail
* when performing the wrap.
*/
u32
gss_wrap(struct gss_ctx *ctx_id,
int offset,
struct xdr_buf *buf,
struct page **inpages)
{
return ctx_id->mech_type->gm_ops
->gss_wrap(ctx_id, offset, buf, inpages);
}
u32
gss_unwrap(struct gss_ctx *ctx_id,
int offset,
int len,
struct xdr_buf *buf)
{
return ctx_id->mech_type->gm_ops
->gss_unwrap(ctx_id, offset, len, buf);
}
/* gss_delete_sec_context: free all resources associated with context_handle.
* Note this differs from the RFC 2744-specified prototype in that we don't
* bother returning an output token, since it would never be used anyway. */
u32
gss_delete_sec_context(struct gss_ctx **context_handle)
{
dprintk("RPC: gss_delete_sec_context deleting %p\n",
*context_handle);
if (!*context_handle)
return GSS_S_NO_CONTEXT;
if ((*context_handle)->internal_ctx_id)
(*context_handle)->mech_type->gm_ops
->gss_delete_sec_context((*context_handle)
->internal_ctx_id);
gss_mech_put((*context_handle)->mech_type);
kfree(*context_handle);
*context_handle=NULL;
return GSS_S_COMPLETE;
}