ext4: avoid potential data overflow in next_linear_group

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[ Upstream commit 60c672b7f2 ]

ngroups is ext4_group_t (unsigned int) while next_linear_group treat it
in int. If ngroups is bigger than max number described by int, it will
be treat as a negative number. Then "return group + 1 >= ngroups ? 0 :
group + 1;" may keep returning 0.
Switch int to ext4_group_t in next_linear_group to fix the overflow.

Fixes: 196e402adf ("ext4: improve cr 0 / cr 1 group scanning")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Kemeng Shi 2023-08-01 22:31:56 +08:00 • committed by Greg Kroah-Hartman

parent 83a9d5f5ec

commit f168ffe467

1 changed files with 3 additions and 2 deletions

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fs/ext4/mballoc.c

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