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 <yuehaibing@xxxxxxxxxx> --- 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))); + min_t(u32, len, sizeof(*item))); if (len < sizeof(*item)) need_reset = 1; if (!need_reset && btrfs_root_generation(item)