[src/trunk]: src/lib/libusbhid lib/libusbhid: Fix possible left shift changes...

[fox <fox%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/588daf54dfeb
branches:  trunk
changeset: 1008882:588daf54dfeb
user:      fox <fox%NetBSD.org@localhost>
date:      Sat Apr 04 21:23:04 2020 +0000

description:
lib/libusbhid: Fix possible left shift changes signedness bit.

This bug was reported by UBSan runs.

lib/libusbhid/usage.c:247:27
lib/libusbhid/usage.c:244:28
lib/libusbhid/usage.c:235:13

Can result in left shift changes signedness bit as a side effect positive number
can go negative, cast it to unsigned for the operation and silence the issue.

Reviewed by: kamil@

diffstat:

 lib/libusbhid/usage.c |  10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diffs (39 lines):

diff -r e557de3f24a8 -r 588daf54dfeb lib/libusbhid/usage.c
--- a/lib/libusbhid/usage.c     Sat Apr 04 21:21:35 2020 +0000
+++ b/lib/libusbhid/usage.c     Sat Apr 04 21:23:04 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usage.c,v 1.10 2016/01/02 21:58:10 christos Exp $      */
+/*     $NetBSD: usage.c,v 1.11 2020/04/04 21:23:04 fox Exp $   */
 
 /*
  * Copyright (c) 1999 Lennart Augustsson <augustss%NetBSD.org@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: usage.c,v 1.10 2016/01/02 21:58:10 christos Exp $");
+__RCSID("$NetBSD: usage.c,v 1.11 2020/04/04 21:23:04 fox Exp $");
 
 #include <assert.h>
 #include <ctype.h>
@@ -232,7 +232,7 @@
                if (strncmp(pages[k].name, name, len) == 0)
                        goto found;
        if (sscanf(name, "%x:%x", &k, &j) == 2) {
-               return (k << 16) | j;
+               return (((uint32_t)k) << 16) | j;
        }
        return -1;
  found:
@@ -241,9 +241,9 @@
                if (pages[k].page_contents[j].usage == -1) {
                        if (sscanf(sep, fmtcheck(
                            pages[k].page_contents[j].name, "%u"), &l) == 1) {
-                               return (pages[k].usage << 16) | l;
+                               return (((uint32_t)pages[k].usage) << 16) | l;
                        }
                } else if (strcmp(pages[k].page_contents[j].name, sep) == 0)
-                       return (pages[k].usage << 16) | pages[k].page_contents[j].usage;
+                       return (((uint32_t)pages[k].usage) << 16) | pages[k].page_contents[j].usage;
        return (-1);
 }