gfs2: Fix invalid metadata access in punch_hole
In punch_hole(), when the offset lies in the final block for a given
height, there is no hole to punch, but the maximum size check fails to
detect that. Consequently, punch_hole() will try to punch a hole beyond
the end of the metadata and fail. Fix the maximum size check.
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index d9ccfd2..6431754 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1718,7 +1718,8 @@
struct buffer_head *dibh, *bh;
struct gfs2_holder rd_gh;
unsigned int bsize_shift = sdp->sd_sb.sb_bsize_shift;
- u64 lblock = (offset + (1 << bsize_shift) - 1) >> bsize_shift;
+ unsigned int bsize = 1 << bsize_shift;
+ u64 lblock = (offset + bsize - 1) >> bsize_shift;
__u16 start_list[GFS2_MAX_META_HEIGHT];
__u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL;
unsigned int start_aligned, end_aligned;
@@ -1729,7 +1730,7 @@
u64 prev_bnr = 0;
__be64 *start, *end;
- if (offset >= maxsize) {
+ if (offset + bsize - 1 >= maxsize) {
/*
* The starting point lies beyond the allocated metadata;
* there are no blocks to deallocate.
