From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 26 Jan 2016 18:02:12 +0000 (+0100)
Subject: machined: add early checks for unrealistically large image/pool sizes
X-Git-Tag: v229.1~1^2~45
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=69db37b5fbcf6d4d26839860d5e067a45f3f7023

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 5f77a556c..7d0d2bd81 100644
--- 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);
+
+}