From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
---
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 4eebcec4aae6..aa36e7daf82c 100644
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -256,6 +256,9 @@ 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++;
