Patch "NFSD: Add a helper to decode state_protect4_a" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSD: Add a helper to decode state_protect4_a

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-add-a-helper-to-decode-state_protect4_a.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b2482e308911b50d22e4e28265462a0644071ab0
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Mon Nov 2 15:19:12 2020 -0500

    NFSD: Add a helper to decode state_protect4_a
    
    [ Upstream commit 523ec6ed6fb80fd1537d748a06bffd060a8b3235 ]
    
    Refactor for clarity.
    
    Also, remove a stale comment. Commit ed94164398c9 ("nfsd: implement
    machine credential support for some operations") added support for
    SP4_MACH_CRED, so state_protect_a is no longer completely ignored.
    
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d402ca0b535f0..e7ec7593eaaa3 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3089,7 +3089,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
 	rpc_ntop(sa, addr_str, sizeof(addr_str));
 	dprintk("%s rqstp=%p exid=%p clname.len=%u clname.data=%p "
-		"ip_addr=%s flags %x, spa_how %d\n",
+		"ip_addr=%s flags %x, spa_how %u\n",
 		__func__, rqstp, exid, exid->clname.len, exid->clname.data,
 		addr_str, exid->flags, exid->spa_how);
 
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 8c5701367e4af..6a4ab81e01ffc 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1531,25 +1531,13 @@ nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
 }
 
 static __be32
-nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
-			 struct nfsd4_exchange_id *exid)
+nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
+			      struct nfsd4_exchange_id *exid)
 {
-	DECODE_HEAD;
-	int dummy;
-
-	READ_BUF(NFS4_VERIFIER_SIZE);
-	COPYMEM(exid->verifier.data, NFS4_VERIFIER_SIZE);
+	__be32 status;
 
-	status = nfsd4_decode_opaque(argp, &exid->clname);
-	if (status)
+	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
 		return nfserr_bad_xdr;
-
-	READ_BUF(4);
-	exid->flags = be32_to_cpup(p++);
-
-	/* Ignore state_protect4_a */
-	READ_BUF(4);
-	exid->spa_how = be32_to_cpup(p++);
 	switch (exid->spa_how) {
 	case SP4_NONE:
 		break;
@@ -1564,9 +1552,31 @@ nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
 			return status;
 		break;
 	default:
-		goto xdr_error;
+		return nfserr_bad_xdr;
 	}
 
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
+			 struct nfsd4_exchange_id *exid)
+{
+	DECODE_HEAD;
+	int dummy;
+
+	status = nfsd4_decode_verifier4(argp, &exid->verifier);
+	if (status)
+		return status;
+	status = nfsd4_decode_opaque(argp, &exid->clname);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_state_protect4_a(argp, exid);
+	if (status)
+		return status;
+
 	READ_BUF(4);    /* nfs_impl_id4 array length */
 	dummy = be32_to_cpup(p++);
 
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 6245004a9993b..232529bc1b798 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -433,7 +433,7 @@ struct nfsd4_exchange_id {
 	u32		flags;
 	clientid_t	clientid;
 	u32		seqid;
-	int		spa_how;
+	u32		spa_how;
 	u32             spo_must_enforce[3];
 	u32             spo_must_allow[3];
 	struct xdr_netobj nii_domain;