fix vulnerability in bspatch
Patches with control data tuples with negative numbers in the first
and/or second can cause bspatch to write to arbitrary locations in the
heap.
Change-Id: I8c5d81948be773e6483241131d3d166b6da27cb8
diff --git a/applypatch/bspatch.c b/applypatch/bspatch.c
index 2e80f81..1dc7ab1 100644
--- a/applypatch/bspatch.c
+++ b/applypatch/bspatch.c
@@ -205,6 +205,11 @@
ctrl[1] = offtin(buf+8);
ctrl[2] = offtin(buf+16);
+ if (ctrl[0] < 0 || ctrl[1] < 0) {
+ printf("corrupt patch (negative byte counts)\n");
+ return 1;
+ }
+
// Sanity check
if (newpos + ctrl[0] > *new_size) {
printf("corrupt patch (new file overrun)\n");