From 0cc22b028e3ef4ef75651820183aa7b7e820b98b Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Mon, 25 Sep 2017 12:23:03 +0200
Subject: [PATCH] vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsets
References: bsc#1085535,bsc#1070995
Patch-mainline: v4.14-rc3
Git-commit: fc46820b27a2d9a46f7e90c9ceb4a64a1bc5fab8
Stable-commit: 0cc22b028e3ef4ef75651820183aa7b7e820b98b

commit fc46820b27a2d9a46f7e90c9ceb4a64a1bc5fab8 upstream.

In generic_file_llseek_size, return -ENXIO for negative offsets as well
as offsets beyond EOF.  This affects filesystems which don't implement
SEEK_HOLE / SEEK_DATA internally, possibly because they don't support
holes.

Fixes xfstest generic/448.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---
 fs/read_write.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 0cc7033aa413..52872c1e57dd 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -112,7 +112,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence,
 		 * In the generic case the entire file is data, so as long as
 		 * offset isn't at the end of the file then the offset is data.
 		 */
-		if (offset >= eof)
+		if ((unsigned long long)offset >= eof)
 			return -ENXIO;
 		break;
 	case SEEK_HOLE:
@@ -120,7 +120,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence,
 		 * There is a virtual hole at the end of the file, so as long as
 		 * offset isn't i_size or larger, return i_size.
 		 */
-		if (offset >= eof)
+		if ((unsigned long long)offset >= eof)
 			return -ENXIO;
 		offset = eof;
 		break;
-- 
2.16.2