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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2020-10-02 00:21:48 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-10-18 16:37:13 +0200 |
| commit | af8c53c8bc087459b1aadd4c94805d8272358d79 (patch) | |
| tree | fc3cf9709f023badf83b48cf536dab748d749dc2 | |
| parent | ext4: make mb_check_counter per group (diff) | |
| download | linux-af8c53c8bc087459b1aadd4c94805d8272358d79.tar.xz linux-af8c53c8bc087459b1aadd4c94805d8272358d79.zip | |
ext4: limit entries returned when counting fsmap records
If userspace asked fsmap to try to count the number of entries, we cannot
return more than UINT_MAX entries because fmh_entries is u32.
Therefore, stop counting if we hit this limit or else we will waste time
to return truncated results.
Fixes: 0c9ec4beecac ("ext4: support GETFSMAP ioctls")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20201001222148.GA49520@magnolia
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/fsmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/ext4/fsmap.c b/fs/ext4/fsmap.c index 005c0ae95a0e..b232c2767534 100644 --- a/fs/ext4/fsmap.c +++ b/fs/ext4/fsmap.c @@ -108,6 +108,9 @@ static int ext4_getfsmap_helper(struct super_block *sb, /* Are we just counting mappings? */ if (info->gfi_head->fmh_count == 0) { + if (info->gfi_head->fmh_entries == UINT_MAX) + return EXT4_QUERY_RANGE_ABORT; + if (rec_fsblk > info->gfi_next_fsblk) info->gfi_head->fmh_entries++; |