[PATCH] Fix implicit signed to unsigned conversion in PVM_VAL_BOX

[Tim Rühsen]

Found by libFuzzer:
pvm-program.c:74:11: runtime error: implicit conversion from type 'int' of
value -8 (32-bit, signed) to type 'unsigned long' changed the value to
18446744073709551608 (64-bit, unsigned)

2020-04-10  Tim Rühsen  <address@hidden>

       * lib/pvm.h (PVM_VAL_BOX): Fix implicit signed
       to unsigned conversion.
---
 ChangeLog | 5 +++++
 lib/pvm.h | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/pvm.h b/lib/pvm.h
index 3fbb513b..e1a06d65 100644
--- a/lib/pvm.h
+++ b/lib/pvm.h
@@ -143,7 +143,7 @@ pvm_val pvm_make_ulong (uint64_t value, int size);
    all pointers are aligned to 8 bytes.  The allocator for the boxed
    values makes sure this is always the case.  */

-#define PVM_VAL_BOX(V) ((pvm_val_box) ((((uintptr_t) V) & ~0x7)))
+#define PVM_VAL_BOX(V) ((pvm_val_box) ((((uintptr_t) V) & ~0x7U)))

 /* This constructor should be used in order to build boxes.  */

--
2.26.0