Re: sysctl: Fixing "second level name in XX. is invalid" on trailing period

[Neel Chauhan]

On 2023-08-29 14:23, Theo Buehler wrote:

+       if (string[strlen(string) - 1] == '.')
+               buf[strlen(string) - 1] = '\0';

Careful with out-of-bounds accesses. What if string is "" ? Probably
easiest to do "len = strlen(string);" and if (len > 0 && ...).

Good catch!

Does this look better:

Index: sbin/sysctl/sysctl.c
===================================================================
RCS file: /cvs/src/sbin/sysctl/sysctl.c,v
retrieving revision 1.259
diff -u -p -u -r1.259 sysctl.c
--- sbin/sysctl/sysctl.c        17 May 2023 22:12:51 -0000      1.259
+++ sbin/sysctl/sysctl.c        29 Aug 2023 21:36:19 -0000
@@ -377,6 +377,9 @@ parse(char *string, int flags)

        (void)strlcpy(buf, string, sizeof(buf));
        bufp = buf;
+       len = strlen(string);
+       if (len > 0 && string[len - 1] == '.')
+               buf[len - 1] = '\0';
        if ((cp = strchr(string, '=')) != NULL) {
                *strchr(buf, '=') = '\0';
                *cp++ = '\0';