From: Murphy Zhou <jencce.kernel@gmail.com>
Date: Wed, 18 Mar 2020 20:43:38 +0800
Subject: [PATCH] CIFS: check new file size when extending file by fallocate
Git-commit: ef4a632ccc1c7d3fb71a5baae85b79af08b7f94b
References: bsc#1144333
Patch-mainline: v5.6

xfstests generic/228 checks if fallocate respect RLIMIT_FSIZE.
After fallocate mode 0 extending enabled, we can hit this failure.
Fix this by check the new file size with vfs helper, return
error if file size is larger then RLIMIT_FSIZE(ulimit -f).

This patch has been tested by LTP/xfstests aginst samba and
Windows server.

Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/smb2ops.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index b0759c8aa6f5..9c9258fc8756 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3255,6 +3255,10 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
 	 * Extending the file
 	 */
 	if ((keep_size == false) && i_size_read(inode) < off + len) {
+		rc = inode_newsize_ok(inode, off + len);
+		if (rc)
+			goto out;
+
 		if ((cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) == 0)
 			smb2_set_sparse(xid, tcon, cfile, inode, false);
 
-- 
2.26.2