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@xxxxxxxxxxxxxxx # v4.9+
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 11 ++++-------
fs/nfs/nfs4xdr.c | 2 +-
include/linux/nfs_xdr.h | 2 +-
3 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 18ca6879d8de..0cd98e253e23 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7461,7 +7461,7 @@ static void nfs4_exchange_id_done(struct rpc_task *task, void *data)
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:
@@ -7498,7 +7498,6 @@ static const struct rpc_call_ops nfs4_exchange_id_call_ops = {
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,
@@ -7522,8 +7521,7 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
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)
@@ -7564,9 +7562,8 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
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
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index fa3eb361d4f8..37c8af003275 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1785,7 +1785,7 @@ static void encode_exchange_id(struct xdr_stream *xdr,
int len = 0;
encode_op_hdr(xdr, OP_EXCHANGE_ID, decode_exchange_id_maxsz, hdr);
- encode_nfs4_verifier(xdr, args->verifier);
+ encode_nfs4_verifier(xdr, &args->verifier);
encode_string(xdr, strlen(args->client->cl_owner_id),
args->client->cl_owner_id);
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index ca3bcc4ed4e5..62cbcb842f99 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1235,7 +1235,7 @@ struct nfs41_state_protection {
struct nfs41_exchange_id_args {
struct nfs_client *client;
- nfs4_verifier *verifier;
+ nfs4_verifier verifier;
u32 flags;
struct nfs41_state_protection state_protect;
};
--
2.13.3
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
