[PATCH] erofs: fix validation in z_erofs_do_map_blocks()

[Noboru Asai]

In case of reading fragment data, map->m_plen is invalid.

Fixes: c505feba4c0d ("erofs: validate the extent length for uncompressed pclusters")
Signed-off-by: Noboru Asai <asai at sijam.com>
---
 fs/erofs/zmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 8bf6d30518b6..902b166a5a5e 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -572,7 +572,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	}
 
 	if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) {
-		if (map->m_llen > map->m_plen) {
+		if (!(map->m_flags & EROFS_MAP_FRAGMENT) && (map->m_llen > map->m_plen) {
 			DBG_BUGON(1);
 			err = -EFSCORRUPTED;
 			goto unmap_out;
-- 
2.39.2