gfs2: Fix invalid metadata access in punch_hole

[ Upstream commit c95346ac918c5badf51b9a7ac58a26d3bd5bb224 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Andrew Price 2024-03-11 16:40:36 +01:00 committed by Greg Kroah-Hartman
parent e29758e73e
commit 6eb0d6e6d3
1 changed files with 3 additions and 2 deletions

View File

@ -1715,7 +1715,8 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length)
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;
@ -1726,7 +1727,7 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length)
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.