nfsd: avoid a NULL dereference in __cld_pipe_upcall()

If the rpc_pipefs is unmounted, then the rpc_pipe->dentry becomes NULL
and dereferencing the dentry->d_sb will trigger an oops.  The only
reason we're doing that is to determine the nfsd_net, which could
instead be passed in by the caller.  So do that instead.

Fixes: 11a60d1592 ("nfsd: add a "GetVersion" upcall for nfsdcld")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Scott Mayhew 2020-07-10 16:33:07 -04:00 committed by Chuck Lever
parent 94415b06eb
commit df60446cd1

View File

@ -747,13 +747,11 @@ struct cld_upcall {
};
static int
__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg)
__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
{
int ret;
struct rpc_pipe_msg msg;
struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
struct nfsd_net *nn = net_generic(pipe->dentry->d_sb->s_fs_info,
nfsd_net_id);
memset(&msg, 0, sizeof(msg));
msg.data = cmsg;
@ -773,7 +771,7 @@ __cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg)
}
static int
cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg)
cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
{
int ret;
@ -782,7 +780,7 @@ cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg)
* upcalls queued.
*/
do {
ret = __cld_pipe_upcall(pipe, cmsg);
ret = __cld_pipe_upcall(pipe, cmsg, nn);
} while (ret == -EAGAIN);
return ret;
@ -1115,7 +1113,7 @@ nfsd4_cld_create(struct nfs4_client *clp)
memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
clp->cl_name.len);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret) {
ret = cup->cu_u.cu_msg.cm_status;
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
@ -1180,7 +1178,7 @@ nfsd4_cld_create_v2(struct nfs4_client *clp)
} else
cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
ret = cld_pipe_upcall(cn->cn_pipe, cmsg);
ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
if (!ret) {
ret = cmsg->cm_status;
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
@ -1218,7 +1216,7 @@ nfsd4_cld_remove(struct nfs4_client *clp)
memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
clp->cl_name.len);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret) {
ret = cup->cu_u.cu_msg.cm_status;
clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
@ -1261,7 +1259,7 @@ nfsd4_cld_check_v0(struct nfs4_client *clp)
memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
clp->cl_name.len);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret) {
ret = cup->cu_u.cu_msg.cm_status;
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
@ -1404,7 +1402,7 @@ nfsd4_cld_grace_start(struct nfsd_net *nn)
}
cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret)
ret = cup->cu_u.cu_msg.cm_status;
@ -1432,7 +1430,7 @@ nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret)
ret = cup->cu_u.cu_msg.cm_status;
@ -1460,7 +1458,7 @@ nfsd4_cld_grace_done(struct nfsd_net *nn)
}
cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret)
ret = cup->cu_u.cu_msg.cm_status;
@ -1524,7 +1522,7 @@ nfsd4_cld_get_version(struct nfsd_net *nn)
goto out_err;
}
cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
if (!ret) {
ret = cup->cu_u.cu_msg.cm_status;
if (ret)