[PATCH 4.13 037/109] ext4: in ext4_seek_{hole,data}, return -ENXIO for negative offsets

Greg Kroah-Hartman
2017-09-24T20:59:14Z

From: Darrick J. Wong <darrick.wong@oracle.com>

commit 1bd8d6cd3e413d64e543ec3e69ff43e75a1cf1ea upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ext4/file.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -595,7 +595,7 @@ static loff_t ext4_seek_data(struct file
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
inode_lock(inode);

isize = i_size_read(inode);
- if (offset >= isize) {
+ if (offset < 0 || offset >= isize) {
inode_unlock(inode);
return -ENXIO;
}