[hackers] [sbase] od: Don't advance past end of type string || Michael Forney

From: <git_AT_suckless.org>
Date: Sat, 9 Jul 2016 11:17:21 +0200 (CEST)

commit 49e1854600bca3b2efbddd365d7b328fbcd0ced6
Author: Michael Forney <mforney_AT_mforney.org>
AuthorDate: Fri Jul 8 10:24:08 2016 -0700
Commit: sin <sin_AT_2f30.org>
CommitDate: Sat Jul 9 10:17:16 2016 +0100

    od: Don't advance past end of type string
    
    Currently, if you specify -t x, then s is advanced once in the switch statement
    to determine the length, and then once again in the for loop, resulting in a
    read past the end of the argument.
    
    Also, use sizeof(int) when no length is specified, as specified by POSIX.

diff --git a/od.c b/od.c
index c448ac5..9b83501 100644
--- a/od.c
+++ b/od.c
_AT_@ -196,7 +196,7 @@ main(int argc, char *argv[])
 {
         FILE *fp;
         struct type *t;
- int ret = 0;
+ int ret = 0, len;
         char *s;
 
         big_endian = (*(uint16_t *)"\0\xff" == 0xff);
_AT_@ -244,30 +244,28 @@ main(int argc, char *argv[])
                         case 'o':
                         case 'u':
                         case 'x':
- t = emalloc(sizeof(*t));
- t->format = *s;
                                 /* todo: allow multiple digits */
                                 if (*(s+1) > '0' && *(s+1) <= '9') {
- t->len = *(++s) - '0';
+ len = *(s+1) - '0';
                                 } else {
- switch (*(++s)) {
+ switch (*(s+1)) {
                                         case 'C':
- t->len = sizeof(char);
+ len = sizeof(char);
                                                 break;
                                         case 'S':
- t->len = sizeof(short);
+ len = sizeof(short);
                                                 break;
                                         case 'I':
- t->len = sizeof(int);
+ len = sizeof(int);
                                                 break;
                                         case 'L':
- t->len = sizeof(long);
+ len = sizeof(long);
                                                 break;
                                         default:
- t->len = 4;
+ len = sizeof(int);
                                         }
                                 }
- TAILQ_INSERT_TAIL(&head, t, entry);
+ addtype(*s++, len);
                                 break;
                         default:
                                 usage();
Received on Sat Jul 09 2016 - 11:17:21 CEST