diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2020-10-01 15:21:48 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-29 09:07:11 +0100 |
| commit | 7b9009bc09f35701383f0541bee21bff1b7c0b40 (patch) | |
| tree | 567a2af7d57916d34d09c4ccce8d7d307de13293 /fs | |
| parent | 4a90077585b43757e7d6a0fac513177db2f6870b (diff) | |
ext4: limit entries returned when counting fsmap records
[ Upstream commit af8c53c8bc087459b1aadd4c94805d8272358d79 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -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 7ec340898598..1a4d42a1b161 100644 --- a/fs/ext4/fsmap.c +++ b/fs/ext4/fsmap.c @@ -121,6 +121,9 @@ 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++; |