Messages in this thread | | | From | Timofey Titovets <> | Date | Sun, 24 Aug 2014 12:44:11 +0300 | Subject | Re: [PATCH] fs: btrfs: fix potential overflow |
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2014-08-24 8:41 GMT+03:00 Brian Norris <computeaboversforpeace@gmail.com>: > It looks like this intended to be 64-bit arithmetic, but it's actually > performed as 32-bit. Fix that. (Note that 'increment' was being > initialized twice, so this patch removes one of those.) > > Caught by Coverity Scan (CID 1201422). > > Signed-off-by: Brian Norris <computersforpeace@gmail.com> > --- > Untested > > fs/btrfs/scrub.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c > index b6d198f5181e..b1a8127737b4 100644 > --- a/fs/btrfs/scrub.c > +++ b/fs/btrfs/scrub.c > @@ -2320,26 +2320,26 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, > do_div(nstripes, map->stripe_len); > if (map->type & BTRFS_BLOCK_GROUP_RAID0) { > offset = map->stripe_len * num; > - increment = map->stripe_len * map->num_stripes; > + increment *= map->num_stripes; > mirror_num = 1; > } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { > int factor = map->num_stripes / map->sub_stripes; > offset = map->stripe_len * (num / map->sub_stripes); > - increment = map->stripe_len * factor; > + increment *= factor; > mirror_num = num % map->sub_stripes + 1; > } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { > - increment = map->stripe_len; > + increment *= 1; Why? I think multiple by one is useless or i miss something?
> mirror_num = num % map->num_stripes + 1; > } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { > - increment = map->stripe_len; > + increment *= 1; Same as above.
> mirror_num = num % map->num_stripes + 1; > } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | > BTRFS_BLOCK_GROUP_RAID6)) { > get_raid56_logic_offset(physical, num, map, &offset); > - increment = map->stripe_len * nr_data_stripes(map); > + increment *= nr_data_stripes(map); > mirror_num = 1; > } else { > - increment = map->stripe_len; > + increment *= 1; Same. > mirror_num = 1; > } > > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
-- Have a nice day, Timofey.
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