Messages in this thread Patch in this message | | | From | Brian Norris <> | Subject | [PATCH] fs: btrfs: fix potential overflow | Date | Sat, 23 Aug 2014 22:41:21 -0700 |
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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; mirror_num = num % map->num_stripes + 1; } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { - increment = map->stripe_len; + increment *= 1; 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; mirror_num = 1; } -- 1.7.9.5
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