4.15-stable review patch. If anyone has any objections, please let me know.
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From: Andreas Gruenbacher agruenba@redhat.com
commit 3b5da96e4585a2788da6a07619bda3518d76eb30 upstream.
It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for block_map"' introduced another bug in gfs2_iomap_begin that can cause gfs2_block_map to set bh->b_size of an actual buffer to 0. This can lead to arbitrary incorrect behavior including crashes or disk corruption. Revert the incorrect part of that commit.
Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Bob Peterson rpeterso@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/gfs2/bmap.c | 3 --- 1 file changed, 3 deletions(-)
--- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -811,9 +811,6 @@ do_alloc: iomap->length = hole_size(inode, lblock, &mp); else iomap->length = size - pos; - } else { - if (height <= ip->i_height) - iomap->length = hole_size(inode, lblock, &mp); } goto out_release; }