ext4: unify the type of flexbg_size to unsigned int

stable inclusion
from stable-v5.10.210
commit b9601924226976c610e8966ea71e7b9314fb41c7
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9BV4P
CVE: CVE-2023-52622

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b9601924226976c610e8966ea71e7b9314fb41c7



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[ Upstream commit 658a52344fb139f9531e7543a6e0015b630feb38 ]

The maximum value of flexbg_size is 2^31, but the maximum value of int
is (2^31 - 1), so overflow may occur when the type of flexbg_size is
declared as int.

For example, when uninit_mask is initialized in ext4_alloc_group_tables(),
if flexbg_size == 2^31, the initialized uninit_mask is incorrect, and this
may causes set_flexbg_block_bitmap() to trigger a BUG_ON().

Therefore, the flexbg_size type is declared as unsigned int to avoid
overflow and memory waste.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231023013057.2117948-2-libaokun1@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lin Yujun <linyujun809@huawei.com>
Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com>