diff options
| author | Kemeng Shi | 2023-08-01 22:31:56 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-09-13 09:42:46 +0200 |
| commit | e0f5698757ab786830a59a80dc8054b08c7cd400 (patch) | |
| tree | 65c1e932aec92df6c54503a4662f5d072474f588 | |
| parent | 772ca4bc1d0d21320ef2ecc0f9e4f90ea85a035d (diff) | |
ext4: avoid potential data overflow in next_linear_group
[ Upstream commit 60c672b7f2d1e5dd1774f2399b355c9314e709f8 ]
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: 196e402adf2e ("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>
| -rw-r--r-- | fs/ext4/mballoc.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 20d02cc0a17a..016925b1a090 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -966,8 +966,9 @@ static inline int should_optimize_scan(struct ext4_allocation_context *ac) * Return next linear group for allocation. If linear traversal should not be * performed, this function just returns the same group */ -static int -next_linear_group(struct ext4_allocation_context *ac, int group, int ngroups) +static ext4_group_t +next_linear_group(struct ext4_allocation_context *ac, ext4_group_t group, + ext4_group_t ngroups) { if (!should_optimize_scan(ac)) goto inc_and_return; |