From: "Darrick J. Wong" <darrick.wong@oracle.com>
Subject: ext4: in ext4_seek_{hole,data}, return -ENXIO for negative offsets
Git-commit: 1bd8d6cd3e413d64e543ec3e69ff43e75a1cf1ea
Patch-mainline: v4.14-rc1
References: bsc#1068897

In the ext4 implementations of SEEK_HOLE and SEEK_DATA, make sure we
return -ENXIO for negative offsets instead of banging around inside
the extent code and returning -EFSCORRUPTED.

Reported-by: Mateusz S <muttdini@gmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org # 4.6

Acked-by: Jeff Mahoney <jeffm@suse.com>
---
 fs/ext4/file.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 0d7cf0cc9b87..86ea1d92839a 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -595,7 +595,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 	inode_lock(inode);
 
 	isize = i_size_read(inode);
-	if (offset >= isize) {
+	if (offset < 0 || offset >= isize) {
 		inode_unlock(inode);
 		return -ENXIO;
 	}
@@ -658,7 +658,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 	inode_lock(inode);
 
 	isize = i_size_read(inode);
-	if (offset >= isize) {
+	if (offset < 0 || offset >= isize) {
 		inode_unlock(inode);
 		return -ENXIO;
 	}