[src/trunk]: src/sys/kern Avoid dereferencing l in sysctl_lookup(), because i...

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

details:   https://anonhg.NetBSD.org/src/rev/4c5b1a3403b7
branches:  trunk
changeset: 556855:4c5b1a3403b7
user:      atatat <atatat%NetBSD.org@localhost>
date:      Mon Dec 29 04:19:28 2003 +0000

description:
Avoid dereferencing l in sysctl_lookup(), because it can be NULL.

Note one point where a possibility of a fault exists.

diffstat:

 sys/kern/kern_sysctl.c |  11 +++++------
 1 files changed, 5 insertions(+), 6 deletions(-)

diffs (46 lines):

diff -r 6ad42ea4b801 -r 4c5b1a3403b7 sys/kern/kern_sysctl.c
--- a/sys/kern/kern_sysctl.c    Mon Dec 29 04:16:25 2003 +0000
+++ b/sys/kern/kern_sysctl.c    Mon Dec 29 04:19:28 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sysctl.c,v 1.156 2003/12/29 04:16:25 atatat Exp $ */
+/*     $NetBSD: kern_sysctl.c,v 1.157 2003/12/29 04:19:28 atatat Exp $ */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -75,7 +75,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.156 2003/12/29 04:16:25 atatat Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.157 2003/12/29 04:19:28 atatat Exp $");
 
 #include "opt_defcorename.h"
 #include "opt_insecure.h"
@@ -1310,7 +1310,6 @@
 int
 sysctl_lookup(SYSCTLFN_RWARGS)
 {
-       struct proc *p = l->l_proc;
        int error, rw;
        size_t sz, len;
        void *d;
@@ -1327,8 +1326,8 @@
        /*
         * some nodes are private, so only root can look into them.
         */
-       if ((rnode->sysctl_flags & SYSCTL_PRIVATE) &&
-           (error = suser(p->p_ucred, &p->p_acflag)) != 0)
+       if (l != NULL && (rnode->sysctl_flags & SYSCTL_PRIVATE) &&
+           (error = suser(l->l_proc->p_ucred, &l->l_proc->p_acflag)) != 0)
                return (error);
 
        /*
@@ -1383,7 +1382,7 @@
        else
                d = rnode->sysctl_data;
        if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_STRING)
-               sz = strlen(d) + 1;
+               sz = strlen(d) + 1; /* XXX@@@ possible fault here */
        else
                sz = rnode->sysctl_size;
        if (oldp != NULL)