diff options
| -rw-r--r-- | lib/libc/gen/sysctl.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/lib/libc/gen/sysctl.c b/lib/libc/gen/sysctl.c index a5a3d49..b83b439 100644 --- a/lib/libc/gen/sysctl.c +++ b/lib/libc/gen/sysctl.c @@ -51,9 +51,21 @@ sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp, const void *newp, size_t newlen) { int retval; + size_t orig_oldlen; + orig_oldlen = oldlenp ? *oldlenp : 0; retval = __sysctl(name, namelen, oldp, oldlenp, newp, newlen); - if (retval != -1 || errno != ENOENT || name[0] != CTL_USER) + /* + * All valid names under CTL_USER have a dummy entry in the sysctl + * tree (to support name lookups and enumerations) with an + * empty/zero value, and the true value is supplied by this routine. + * For all such names, __sysctl() is used solely to validate the + * name. + * + * Return here unless there was a successful lookup for a CTL_USER + * name. + */ + if (retval || name[0] != CTL_USER) return (retval); if (newp != NULL) { @@ -67,7 +79,7 @@ sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp, switch (name[1]) { case USER_CS_PATH: - if (oldp && *oldlenp < sizeof(_PATH_STDPATH)) { + if (oldp && orig_oldlen < sizeof(_PATH_STDPATH)) { errno = ENOMEM; return -1; } |
