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| author | Kemeng Shi <shikemeng@huaweicloud.com> | 2023-08-01 17:31:56 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-08-03 17:47:29 +0300 |
| commit | 60c672b7f2d1e5dd1774f2399b355c9314e709f8 (patch) | |
| tree | ed46ae5c8c6ebba0512bbc1494ecc57dd382e10d /fs/ext4 | |
| parent | a9ce5993a0f5c0887c8a1b4ffa3b8046fbcfdc93 (diff) | |
| download | linux-60c672b7f2d1e5dd1774f2399b355c9314e709f8.tar.xz | |
ext4: avoid potential data overflow in next_linear_group
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>
Diffstat (limited to 'fs/ext4')
| -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 e07d2a4fbcd1..bf041932c599 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1080,8 +1080,9 @@ 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; |