release/5.2.42/NFS-alloc_nfs_open_context-must-use-the-file-cred-wh.patch

From 1a9a84ba816ba4a7c0ed25ae8e01be9980c517b6 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Fri, 7 Feb 2020 19:32:49 -0500
Subject: [PATCH] NFS: alloc_nfs_open_context() must use the file cred when
 available

commit 1d179d6bd67369a52edea8562154b31ee20be1cc upstream.

If we're creating a nfs_open_context() for a specific file pointer,
we must use the cred assigned to that file.

Fixes: a52458b48af1 ("NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 53777813ca95..2c9b7bbf0fac 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -957,16 +957,16 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
 						struct file *filp)
 {
 	struct nfs_open_context *ctx;
-	const struct cred *cred = get_current_cred();
 
 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
-	if (!ctx) {
-		put_cred(cred);
+	if (!ctx)
 		return ERR_PTR(-ENOMEM);
-	}
 	nfs_sb_active(dentry->d_sb);
 	ctx->dentry = dget(dentry);
-	ctx->cred = cred;
+	if (filp)
+		ctx->cred = get_cred(filp->f_cred);
+	else
+		ctx->cred = get_current_cred();
 	ctx->ll_cred = NULL;
 	ctx->state = NULL;
 	ctx->mode = f_mode;
-- 
2.7.4