ext4: in ext4_seek_{hole,data}, return -ENXIO for negative offsets

BugLink: http://bugs.launchpad.net/bugs/1724836
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>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 2db027b29cfbe31df38b417ab6a50f124c305df6..98ea8cbbc6842caa8e292e086e319eefd580c31a 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -558,7 +558,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
        mutex_lock(&inode->i_mutex);
 
        isize = i_size_read(inode);
-       if (offset >= isize) {
+       if (offset < 0 || offset >= isize) {
                mutex_unlock(&inode->i_mutex);
                return -ENXIO;
        }
@@ -621,7 +621,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
        mutex_lock(&inode->i_mutex);
 
        isize = i_size_read(inode);
-       if (offset >= isize) {
+       if (offset < 0 || offset >= isize) {
                mutex_unlock(&inode->i_mutex);
                return -ENXIO;
        }