From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Wed, 20 Feb 2019 05:58:43 +0000 Subject: Re: [PATCH -next] btrfs: Fix type conversion in btrfs_read_root_item Message-Id: <20190220055621.GM17104@kadam> List-Id: References: <20190220030840.188854-1-yuehaibing@huawei.com> In-Reply-To: <20190220030840.188854-1-yuehaibing@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: YueHaibing Cc: Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org On Wed, Feb 20, 2019 at 03:08:40AM +0000, YueHaibing wrote: > btrfs_item_size_nr return value is u32, convert it to int may result > in truncation.Also read_extent_buffer expect a unsigned param, so > min_t should use type u32 to compare. > > Fixes: 8ea05e3a4262 ("Btrfs: introduce subvol uuids and times") > Signed-off-by: YueHaibing > --- > fs/btrfs/root-tree.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c > index 02d1a57af78b..893d12fbfda0 100644 > --- a/fs/btrfs/root-tree.c > +++ b/fs/btrfs/root-tree.c > @@ -21,12 +21,12 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot, > struct btrfs_root_item *item) > { > uuid_le uuid; > - int len; > + u32 len; > int need_reset = 0; > > len = btrfs_item_size_nr(eb, slot); > read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), > - min_t(int, len, (int)sizeof(*item))); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Yeah, min_t() should normally cast to unsigned and the extra cast is silly. > + min_t(u32, len, sizeof(*item))); regards, dan carpenter