machined: add early checks for unrealistically large image/pool sizes

diff --git a/src/basic/io-util.h b/src/basic/io-util.h
index 5f77a556c047112ebffa183b7f573066a3686279..7d0d2bd810e7b37e13a7bf28375d9f3919c50e42 100644 (file)
--- a/src/basic/io-util.h
+++ b/src/basic/io-util.h
@@ -77,3 +77,21 @@ static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 
         return k;
 }
+
+static inline bool FILE_SIZE_VALID(uint64_t l) {
+        /* ftruncate() and friends take an unsigned file size, but actually cannot deal with file sizes larger than
+         * 2^63 since the kernel internally handles it as signed value. This call allows checking for this early. */
+
+        return (l >> 63) == 0;
+}
+
+static inline bool FILE_SIZE_VALID_OR_INFINITY(uint64_t l) {
+
+        /* Same as above, but allows one extra value: -1 as indication for infinity. */
+
+        if (l == (uint64_t) -1)
+                return true;
+
+        return FILE_SIZE_VALID(l);
+
+}