# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 2016-03-17 00:29:29
# Node ID b6ed2505d6cf1d73f7f5c62e7369c4ce65cd3732
# Parent  a2c2dd399f3b9fb84edd75a930e895f0c5e4ad5b

parsers: fix list sizing rounding error (SEC)

CVE-2016-3630 (1/2)

This addresses part of a vulnerability in application of binary
deltas.

diff --git a/mercurial/mpatch.c b/mercurial/mpatch.c
--- a/mercurial/mpatch.c
+++ b/mercurial/mpatch.c
@@ -205,7 +205,7 @@ static struct flist *decode(const char *
 	int pos = 0;
 
 	/* assume worst case size, we won't have many of these lists */
-	l = lalloc(len / 12);
+	l = lalloc(len / 12 + 1);
 	if (!l)
 		return NULL;
 
diff --git a/tests/test-revlog.t b/tests/test-revlog.t
new file mode 100644
--- /dev/null
+++ b/tests/test-revlog.t
@@ -0,0 +1,15 @@
+Test for CVE-2016-3630
+
+  $ hg init
+
+  >>> open("a.i", "w").write(
+  ... """eJxjYGZgZIAAYQYGxhgom+k/FMx8YKx9ZUaKSOyqo4cnuKb8mbqHV5cBCVTMWb1Cwqkhe4Gsg9AD
+  ... Joa3dYtcYYYBAQ8Qr4OqZAYRICPTSr5WKd/42rV36d+8/VmrNpv7NP1jQAXrQE4BqQUARngwVA=="""
+  ... .decode("base64").decode("zlib"))
+
+  $ hg debugindex a.i
+     rev    offset  length  delta linkrev nodeid       p1           p2
+       0         0      19     -1       2 99e0332bd498 000000000000 000000000000
+       1        19      12      0       3 6674f57a23d8 99e0332bd498 000000000000
+  $ hg debugdata a.i 1 2>&1 | grep decoded
+  mpatch.mpatchError: patch cannot be decoded