From: Darrick J. Wong darrick.wong@oracle.com
[ Upstream commit acd1ac3aa22fd58803a12d26b1ab7f70232f8d8d ]
If userspace asked fsmap 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: e89c041338ed ("xfs: implement the GETFSMAP ioctl") Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Chandan Babu R chandanrlinux@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/xfs/xfs_fsmap.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c index c13754e119be1..5b864985bc648 100644 --- a/fs/xfs/xfs_fsmap.c +++ b/fs/xfs/xfs_fsmap.c @@ -255,6 +255,9 @@ xfs_getfsmap_helper(
/* Are we just counting mappings? */ if (info->head->fmh_count == 0) { + if (info->head->fmh_entries == UINT_MAX) + return -ECANCELED; + if (rec_daddr > info->next_daddr) info->head->fmh_entries++;