[PATCH AUTOSEL 4.20 076/105] SUNRPC: Ensure we respect the RPCSEC_GSS sequence number limit

Sasha Levin
2019-02-13T03:00:22Z

From: Trond Myklebust <trondmy@gmail.com>

[ Upstream commit 97b78ae96ba76f4ca2d8f5afee6a2e567ccb8f45 ]

According to RFC2203, the RPCSEC_GSS sequence numbers are bounded to
an upper limit of MAXSEQ = 0x80000000. Ensure that we handle that
correctly.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sunrpc/auth_gss/auth_gss.c | 12 +++++++++---
net/sunrpc/clnt.c | 19 ++++++++++++-------
2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index ba765473d1f0..efeee5586b2a 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1563,8 +1563,10 @@ gss_marshal(struct rpc_task *task, __be32 *p)
cred_len = p++;

spin_lock(&ctx->gc_seq_lock);
- req->rq_seqno = ctx->gc_seq++;
+ req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ;
spin_unlock(&ctx->gc_seq_lock);
+ if (req->rq_seqno == MAXSEQ)
+ goto out_expired;

*p++ = htonl((u32) RPC_GSS_VERSION);
*p++ = htonl((u32) ctx->gc_proc);
@@ -1586,14 +1588,18 @@ gss_marshal(struct rpc_task *task, __be32 *p)
mic.data = (u8 *)(p + 1);
maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
- clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+ goto out_expired;
} else if (maj_stat != 0) {
- printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
+ pr_warn("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
+ task->tk_status = -EIO;
goto out_put_ctx;
}
p = xdr_encode_opaque(p, NULL, mic.len);
gss_put_ctx(ctx);
return p;
+out_expired:
+ clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+ task->tk_status = -EKEYEXPIRED;
out_put_ctx:
gss_put_ctx(ctx);
return NULL;
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 2189fbc4c570..1ee04e0ec4bc 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1740,11 +1740,8 @@ rpc_xdr_encode(struct rpc_task *task)
req->rq_rcvsize);

p = rpc_encode_header(task);
- if (p == NULL) {
- printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
- rpc_exit(task, -EIO);
+ if (p == NULL)
return;
- }

encode = task->tk_msg.rpc_proc->p_encode;
if (encode == NULL)
@@ -1769,10 +1766,17 @@ call_encode(struct rpc_task *task)
/* Did the encode result in an error condition? */
if (task->tk_status != 0) {
/* Was the error nonfatal? */
- if (task->tk_status == -EAGAIN || task->tk_status == -ENOMEM)
+ switch (task->tk_status) {
+ case -EAGAIN:
+ case -ENOMEM:
rpc_delay(task, HZ >> 4);
- else
+ break;
+ case -EKEYEXPIRED:
+ task->tk_action = call_refresh;
+ break;
+ default:
rpc_exit(task, task->tk_status);
+ }
return;
}

@@ -2334,7 +2338,8 @@ rpc_encode_header(struct rpc_task *task)
*p++ = htonl(clnt->cl_vers); /* program version */
*p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
p = rpcauth_marshcred(task, p);
- req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
+ if (p)
+ req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
return p;
}

--
2.19.1