[PATCH] sunrpc: return error if unsupported enctype or cksumtype is encountered

[Kevin Coffman]

Return an error from gss_import_sec_context_kerberos if the
negotiated context contains encryption or checksum types not
supported by the kernel code.

In gss_pipe_downcall(), return EACCES for any errors unless
EAGAIN is returned.  Otherwise, any error such as above results
in mount continually retrying rather than failing.

Signed-off-by: Kevin Coffman <kwc at citi.umich.edu>
---

 net/sunrpc/auth_gss/auth_gss.c      |    2 +-
 net/sunrpc/auth_gss/gss_krb5_mech.c |    8 ++++++--
 net/sunrpc/auth_gss/gss_krb5_seal.c |    1 +
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 53995af..c42362c 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -540,7 +540,7 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 	if (IS_ERR(p)) {
 		err = PTR_ERR(p);
-		gss_msg->msg.errno = (err == -EACCES) ? -EACCES : -EAGAIN;
+		gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 		goto err_release_msg;
 	}
 	gss_msg->ctx = gss_get_ctx(ctx);
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index 9843eac..60c3dba 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -147,13 +147,17 @@ gss_import_sec_context_kerberos(const void *p,
 	p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 	if (IS_ERR(p))
 		goto out_err_free_ctx;
-	if (tmp != SGN_ALG_DES_MAC_MD5)
+	if (tmp != SGN_ALG_DES_MAC_MD5) {
+		p = ERR_PTR(-ENOSYS);
 		goto out_err_free_ctx;
+	}
 	p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 	if (IS_ERR(p))
 		goto out_err_free_ctx;
-	if (tmp != SEAL_ALG_DES)
+	if (tmp != SEAL_ALG_DES) {
+		p = ERR_PTR(-ENOSYS);
 		goto out_err_free_ctx;
+	}
 	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 	if (IS_ERR(p))
 		goto out_err_free_ctx;
diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c
index a0d9faa..cf685bd 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -84,6 +84,7 @@ gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
 	u32			seq_send;
 
 	dprintk("RPC:       gss_krb5_seal\n");
+	BUG_ON(ctx == NULL);
 
 	now = get_seconds();