svn commit: r286813 - stable/10/bin/sh

[Jilles Tjoelker]

Author: jilles
Date: Sat Aug 15 19:58:00 2015
New Revision: 286813
URL: https://svnweb.freebsd.org/changeset/base/286813

Log:
  MFC r284779: sh: Fix some arithmetic undefined behaviour.
  
  Fix shifts of possibly negative numbers found with ubsan and avoid signed
  integer overflow when hashing an extremely long command name.

Modified:
  stable/10/bin/sh/alias.c
  stable/10/bin/sh/exec.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/bin/sh/alias.c
==============================================================================
--- stable/10/bin/sh/alias.c	Sat Aug 15 19:00:38 2015	(r286812)
+++ stable/10/bin/sh/alias.c	Sat Aug 15 19:58:00 2015	(r286813)
@@ -248,7 +248,7 @@ hashalias(const char *p)
 {
 	unsigned int hashval;
 
-	hashval = *p << 4;
+	hashval = (unsigned char)*p << 4;
 	while (*p)
 		hashval+= *p++;
 	return &atab[hashval % ATABSIZE];

Modified: stable/10/bin/sh/exec.c
==============================================================================
--- stable/10/bin/sh/exec.c	Sat Aug 15 19:00:38 2015	(r286812)
+++ stable/10/bin/sh/exec.c	Sat Aug 15 19:58:00 2015	(r286813)
@@ -524,17 +524,16 @@ static struct tblentry **lastcmdentry;
 static struct tblentry *
 cmdlookup(const char *name, int add)
 {
-	int hashval;
+	unsigned int hashval;
 	const char *p;
 	struct tblentry *cmdp;
 	struct tblentry **pp;
 	size_t len;
 
 	p = name;
-	hashval = *p << 4;
+	hashval = (unsigned char)*p << 4;
 	while (*p)
 		hashval += *p++;
-	hashval &= 0x7FFF;
 	pp = &cmdtable[hashval % CMDTABLESIZE];
 	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
 		if (equal(cmdp->cmdname, name))