ref: d21015e34af125d6cc2e4d1200e5ca3c76b8de42
parent: d6cd5823e3053bbcf356715e3a4933aa6f94c6f0
author: JL2210 <larrowe.semaj11@gmail.com>
date: Thu Apr 9 05:46:58 EDT 2020
Fix use of zero-allocated memory
It's possible that the unsigned integer may overflow to zero,
and then we might use zero-allocated memory.
This is incredibly unlikely, and I would even go so far as to say
that this is a false positive. Fix it anyway, to silence this warning:
src/link/patch.c:92:24: warning: Use of zero-allocated memory
stack.buf[stack.size] = value;
~~~~~~~~~~~~~~~~~~~~~ ^
Deal with overflow, and check for zero to get rid of the warning.
Signed-off-by: JL2210 <larrowe.semaj11@gmail.com>
--- a/src/link/patch.c
+++ b/src/link/patch.c
@@ -82,10 +82,18 @@
static void pushRPN(int32_t value)
{ if (stack.size >= stack.capacity) {- stack.capacity *= 2;
+ static const size_t increase_factor = 2;
+
+ if (stack.capacity > SIZE_MAX / increase_factor)
+ err(1, "Overflow in RPN stack resize");
+
+ stack.capacity *= increase_factor;
stack.buf =
realloc(stack.buf, sizeof(*stack.buf) * stack.capacity);
- if (!stack.buf)
+ // || !stack.capacity to fix bogus
+ // zero-size allocation warning from
+ // scan-build, already caught above
+ if (!stack.buf || !stack.capacity)
err(1, "Failed to resize RPN stack");
}