When the client needs to talk to rpc.gssd, we should ensure that the
uid argument is encoded to match the user namespace of the daemon.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
net/sunrpc/auth_gss/auth_gss.c | 60 +++++++++++++++++++++++++---------
1 file changed, 44 insertions(+), 16 deletions(-)
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index e3601dc6c180..6baa8fd77c29 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -269,6 +269,7 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
struct gss_upcall_msg {
refcount_t count;
kuid_t uid;
+ const char *service_name;
struct rpc_pipe_msg msg;
struct list_head list;
struct gss_auth *auth;
@@ -316,6 +317,7 @@ gss_release_msg(struct gss_upcall_msg *gss_msg)
gss_put_ctx(gss_msg->ctx);
rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
gss_put_auth(gss_msg->auth);
+ kfree_const(gss_msg->service_name);
kfree(gss_msg);
}
@@ -410,10 +412,10 @@ gss_upcall_callback(struct rpc_task *task)
gss_release_msg(gss_msg);
}
-static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
+static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg,
+ const struct cred *cred)
{
- struct user_namespace *userns = gss_msg->auth->client->cl_cred ?
- gss_msg->auth->client->cl_cred->user_ns : &init_user_ns;
+ struct user_namespace *userns = cred->user_ns;
uid_t uid = from_kuid_munged(userns, gss_msg->uid);
memcpy(gss_msg->databuf, &uid, sizeof(uid));
@@ -423,12 +425,24 @@ static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
}
+static ssize_t
+gss_v0_upcall(struct file *file, struct rpc_pipe_msg *msg,
+ char __user *buf, size_t buflen)
+{
+ struct gss_upcall_msg *gss_msg = container_of(msg,
+ struct gss_upcall_msg,
+ msg);
+ if (msg->copied == 0)
+ gss_encode_v0_msg(gss_msg, file->f_cred);
+ return rpc_pipe_generic_upcall(file, msg, buf, buflen);
+}
+
static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
const char *service_name,
- const char *target_name)
+ const char *target_name,
+ const struct cred *cred)
{
- struct user_namespace *userns = gss_msg->auth->client->cl_cred ?
- gss_msg->auth->client->cl_cred->user_ns : &init_user_ns;
+ struct user_namespace *userns = cred->user_ns;
struct gss_api_mech *mech = gss_msg->auth->mech;
char *p = gss_msg->databuf;
size_t buflen = sizeof(gss_msg->databuf);
@@ -496,6 +510,25 @@ static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
return -ENOMEM;
}
+static ssize_t
+gss_v1_upcall(struct file *file, struct rpc_pipe_msg *msg,
+ char __user *buf, size_t buflen)
+{
+ struct gss_upcall_msg *gss_msg = container_of(msg,
+ struct gss_upcall_msg,
+ msg);
+ int err;
+ if (msg->copied == 0) {
+ err = gss_encode_v1_msg(gss_msg,
+ gss_msg->service_name,
+ gss_msg->auth->target_name,
+ file->f_cred);
+ if (err)
+ return err;
+ }
+ return rpc_pipe_generic_upcall(file, msg, buf, buflen);
+}
+
static struct gss_upcall_msg *
gss_alloc_msg(struct gss_auth *gss_auth,
kuid_t uid, const char *service_name)
@@ -518,16 +551,11 @@ gss_alloc_msg(struct gss_auth *gss_auth,
refcount_set(&gss_msg->count, 1);
gss_msg->uid = uid;
gss_msg->auth = gss_auth;
- switch (vers) {
- case 0:
- gss_encode_v0_msg(gss_msg);
- break;
- default:
- err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
- if (err)
+ if (service_name) {
+ gss_msg->service_name = kstrdup_const(service_name, GFP_NOFS);
+ if (!gss_msg->service_name)
goto err_put_pipe_version;
}
- kref_get(&gss_auth->kref);
return gss_msg;
err_put_pipe_version:
put_pipe_version(gss_auth->net);
@@ -2121,7 +2149,7 @@ static const struct rpc_credops gss_nullops = {
};
static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
- .upcall = rpc_pipe_generic_upcall,
+ .upcall = gss_v0_upcall,
.downcall = gss_pipe_downcall,
.destroy_msg = gss_pipe_destroy_msg,
.open_pipe = gss_pipe_open_v0,
@@ -2129,7 +2157,7 @@ static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
};
static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
- .upcall = rpc_pipe_generic_upcall,
+ .upcall = gss_v1_upcall,
.downcall = gss_pipe_downcall,
.destroy_msg = gss_pipe_destroy_msg,
.open_pipe = gss_pipe_open_v1,
--
2.21.0
