NFSv4: Fix EXCHANGE_ID corrupt verifier issue
The verifier is allocated on the stack, but the EXCHANGE_ID RPC call was
changed to be asynchronous by commit 8d89bd70bc939. If we interrrupt
the call to rpc_wait_for_completion_task(), we can therefore end up
transmitting random stack contents in lieu of the verifier.
Fixes: 8d89bd70bc939 ("NFS setup async exchange_id")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 93c1d73..c458a1e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7460,7 +7460,7 @@
cdata->res.server_scope = NULL;
}
/* Save the EXCHANGE_ID verifier session trunk tests */
- memcpy(clp->cl_confirm.data, cdata->args.verifier->data,
+ memcpy(clp->cl_confirm.data, cdata->args.verifier.data,
sizeof(clp->cl_confirm.data));
}
out:
@@ -7497,7 +7497,6 @@
static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
u32 sp4_how, struct rpc_xprt *xprt)
{
- nfs4_verifier verifier;
struct rpc_message msg = {
.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_EXCHANGE_ID],
.rpc_cred = cred,
@@ -7521,8 +7520,7 @@
return -ENOMEM;
}
- if (!xprt)
- nfs4_init_boot_verifier(clp, &verifier);
+ nfs4_init_boot_verifier(clp, &calldata->args.verifier);
status = nfs4_init_uniform_client_string(clp);
if (status)
@@ -7563,9 +7561,8 @@
task_setup_data.rpc_xprt = xprt;
task_setup_data.flags =
RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC;
- calldata->args.verifier = &clp->cl_confirm;
- } else {
- calldata->args.verifier = &verifier;
+ memcpy(calldata->args.verifier.data, clp->cl_confirm.data,
+ sizeof(calldata->args.verifier.data));
}
calldata->args.client = clp;
#ifdef CONFIG_NFS_V4_1_MIGRATION