MEDIUM: shctx: forbid shctx to read more than expected

Forbid shctx to read more than expected, it allows you to use a greater
value as a len with shctx_row_data_get(), the size of the destination
buffer for example.

diff --git a/src/shctx.c b/src/shctx.c
index 69da33570d78288b4aeee289ef6b9f264abc04ae..61fd12d3d61823d4cecf0305e1e9069f14d473e3 100644 (file)
--- a/src/shctx.c
+++ b/src/shctx.c
@@ -209,6 +209,10 @@ int shctx_row_data_get(struct shared_context *shctx, struct shared_block *first,
        int count = 0, size = 0, start = -1;
        struct shared_block *block;
 
+       /* can't copy more */
+       if (len > first->len)
+               len = first->len;
+
        block = first;
        count = 0;
        /* Pass through the blocks to copy them */