Re: [f2fs-dev] [PATCH] f2fs-tools: fix overflow bug of start_sector when computing zone_align_start_offset

[Yunlong Song]

Just keep it same with u_int64_t defined in mkfs/f2fs_format.c, and 
c.start_sector * c.sector_size
may be u32 overflow, so add (u_int64_t) before c.start_sector * 
c.sector_size and change the target
value zone_align_start_offset to (u_int64_t).

On 2018/5/26 19:27, Junling Zheng wrote:
> No neet to change zone_align_start_offset to u64, because zone_align_start_offset is always
> smaller than zone_size_bytes, which is u32.
>
> Thanks,
> Junling
>
> On 2018/5/26 16:09, Yunlong Song wrote:
> > zone_align_start_offset should be u64, but config.start_sector is u32,
> > so it may be overflow when computing zone_align_start_offset.
> >
> > Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
> > ---
> >   fsck/resize.c      | 7 ++++---
> >   mkfs/f2fs_format.c | 4 ++--
> >   2 files changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/fsck/resize.c b/fsck/resize.c
> > index d285dd7..8ac7d45 100644
> > --- a/fsck/resize.c
> > +++ b/fsck/resize.c
> > @@ -11,7 +11,8 @@
> >   
> >   static int get_new_sb(struct f2fs_super_block *sb)
> >   {
> > -	u_int32_t zone_size_bytes, zone_align_start_offset;
> > +	u_int32_t zone_size_bytes;
> > +	u_int64_t zone_align_start_offset;
> >   	u_int32_t blocks_for_sit, blocks_for_nat, blocks_for_ssa;
> >   	u_int32_t sit_segments, nat_segments, diff, total_meta_segments;
> >   	u_int32_t total_valid_blks_available;
> > @@ -27,10 +28,10 @@ static int get_new_sb(struct f2fs_super_block *sb)
> >   
> >   	zone_size_bytes = segment_size_bytes * segs_per_zone;
> >   	zone_align_start_offset =
> > -		(c.start_sector * c.sector_size +
> > +		((u_int64_t) c.start_sector * c.sector_size +
> >   		2 * F2FS_BLKSIZE + zone_size_bytes - 1) /
> >   		zone_size_bytes * zone_size_bytes -
> > -		c.start_sector * c.sector_size;
> > +		(u_int64_t) c.start_sector * c.sector_size;
> >   
> >   	set_sb(segment_count, (c.target_sectors * c.sector_size -
> >   				zone_align_start_offset) / segment_size_bytes /
> > diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
> > index 0a99a77..f045e23 100644
> > --- a/mkfs/f2fs_format.c
> > +++ b/mkfs/f2fs_format.c
> > @@ -212,10 +212,10 @@ static int f2fs_prepare_super_block(void)
> >   	set_sb(block_count, c.total_sectors >> log_sectors_per_block);
> >   
> >   	zone_align_start_offset =
> > -		(c.start_sector * c.sector_size +
> > +		((u_int64_t) c.start_sector * c.sector_size +
> >   		2 * F2FS_BLKSIZE + zone_size_bytes - 1) /
> >   		zone_size_bytes * zone_size_bytes -
> > -		c.start_sector * c.sector_size;
> > +		(u_int64_t) c.start_sector * c.sector_size;
> >   
> >   	if (c.start_sector % c.sectors_per_blk) {
> >   		MSG(1, "\t%s: Align start sector number to the page unit\n",
>
>
> .

--
Thanks,
Yunlong Song