From: Trond Myklebust <trondmy@gmail.com>
Date: Tue, 9 Apr 2019 11:46:14 -0400
Subject: [PATCH] SUNRPC/nfs: Fix return value for nfs4_callback_compound()
Git-commit: 83dd59a0b9afc3b1a2642fb5c9b0585b1c08768f
Patch-mainline: v5.2
References: git-fixes

RPC server procedures are normally expected to return a __be32 encoded
status value of type 'enum rpc_accept_stat', however at least one function
wants to return an authentication status of type 'enum rpc_auth_stat'
in the case where authentication fails.
This patch adds functionality to allow this.

Fixes: a4e187d83d88 ("NFS: Don't drop CB requests with invalid principals")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/callback_xdr.c      |    2 +-
 include/linux/sunrpc/svc.h |    2 ++
 net/sunrpc/svc.c           |   27 ++++++++++++++++++++++-----
 3 files changed, 25 insertions(+), 6 deletions(-)

--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -931,7 +931,7 @@ static __be32 nfs4_callback_compound(str
 
 out_invalidcred:
 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
-	return rpc_autherr_badcred;
+	return svc_return_autherr(rqstp, rpc_autherr_badcred);
 }
 
 /*
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -269,6 +269,7 @@ struct svc_rqst {
 #define	RQ_VICTIM	(5)			/* about to be shut down */
 #define	RQ_BUSY		(6)			/* request is busy */
 #define	RQ_DATA		(7)			/* request has data */
+#define RQ_AUTHERR	(8)			/* Request status is auth error */
 	unsigned long		rq_flags;	/* flags field */
 
 	void *			rq_argp;	/* decoded arguments */
@@ -491,6 +491,7 @@ void		   svc_wake_up(struct svc_serv *);
 void		   svc_reserve(struct svc_rqst *rqstp, int space);
 struct svc_pool *  svc_pool_for_cpu(struct svc_serv *serv, int cpu);
 char *		   svc_print_addr(struct svc_rqst *, char *, size_t);
+__be32            svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err);
 unsigned int	   svc_fill_write_vector(struct svc_rqst *rqstp,
 					 struct kvec *first, size_t total);
 char		  *svc_fill_symlink_pathname(struct svc_rqst *rqstp,
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1144,6 +1144,22 @@ void svc_printk(struct svc_rqst *rqstp,
 static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
 #endif
 
+__be32
+svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err)
+{
+	set_bit(RQ_AUTHERR, &rqstp->rq_flags);
+	return auth_err;
+}
+EXPORT_SYMBOL_GPL(svc_return_autherr);
+
+static __be32
+svc_get_autherr(struct svc_rqst *rqstp, __be32 *statp)
+{
+	if (test_and_clear_bit(RQ_AUTHERR, &rqstp->rq_flags))
+		return *statp;
+	return rpc_auth_ok;
+}
+
 /*
  * Common routine for processing the RPC request.
  */
@@ -1295,11 +1311,9 @@ svc_process_common(struct svc_rqst *rqst
 				procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 			goto dropit;
 		}
-		if (*statp == rpc_autherr_badcred) {
-			if (procp->pc_release)
-				procp->pc_release(rqstp, NULL, rqstp->rq_resp);
-			goto err_bad_auth;
-		}
+		auth_stat = svc_get_autherr(rqstp, statp);
+		if (auth_stat != rpc_auth_ok)
+			goto err_release_bad_auth;
 		if (*statp == rpc_success &&
 		    (xdr = procp->pc_encode) &&
 		    !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
@@ -1357,6 +1371,9 @@ err_bad_rpc:
 	svc_putnl(resv, 2);
 	goto sendit;
 
+err_release_bad_auth:
+	if (procp->pc_release)
+		procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 err_bad_auth:
 	dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 	serv->sv_stats->rpcbadauth++;