[src/netbsd-3]: src/sys/kern Pull up revision 1.45 (requested by elad in tick...

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

details:   https://anonhg.NetBSD.org/src/rev/131c177c9e67
branches:  netbsd-3
changeset: 576424:131c177c9e67
user:      tron <tron%NetBSD.org@localhost>
date:      Sat Jul 02 17:54:05 2005 +0000

description:
Pull up revision 1.45 (requested by elad in ticket #487):
>From marius@openbsd:
Add an exec message so that whenever a set-uid/gid process executes a new
image which we may control, the exec does not go by unnoticed.

diffstat:

 sys/kern/kern_systrace.c |  67 +++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 55 insertions(+), 12 deletions(-)

diffs (131 lines):

diff -r b25859762e72 -r 131c177c9e67 sys/kern/kern_systrace.c
--- a/sys/kern/kern_systrace.c  Sat Jul 02 17:53:58 2005 +0000
+++ b/sys/kern/kern_systrace.c  Sat Jul 02 17:54:05 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_systrace.c,v 1.44 2005/02/26 21:34:55 perry Exp $ */
+/*     $NetBSD: kern_systrace.c,v 1.44.2.1 2005/07/02 17:54:05 tron Exp $      */
 
 /*
  * Copyright 2002, 2003 Niels Provos <provos%citi.umich.edu@localhost>
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_systrace.c,v 1.44 2005/02/26 21:34:55 perry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_systrace.c,v 1.44.2.1 2005/07/02 17:54:05 tron Exp $");
 
 #include "opt_systrace.h"
 
@@ -1242,6 +1242,42 @@
        return (error);
 }
 
+void
+systrace_execve(char *path, struct proc *p)
+{
+       struct str_process *strp;
+       struct fsystrace *fst;
+       struct str_message msg;
+       struct str_msg_execve *msg_execve;
+
+       do {
+               systrace_lock();
+               strp = p->p_systrace;
+               if (strp == NULL) {
+                       systrace_unlock();
+                       return;
+               }
+
+               msg_execve = &msg.msg_data.msg_execve;
+               fst = strp->parent;
+               SYSTRACE_LOCK(fst, curlwp);
+               systrace_unlock();
+
+               /*
+                * susers will get the execve call anyway. Also, if
+                * we're not allowed to control the process, escape.
+                */
+               if (fst->issuser ||
+                   fst->p_ruid != p->p_cred->p_ruid ||
+                   fst->p_rgid != p->p_cred->p_rgid) {
+                       SYSTRACE_UNLOCK(fst, curlwp);
+                       return;
+               }
+
+               strlcpy(msg_execve->path, path, sizeof(msg_execve->path));
+       } while (systrace_make_msg(strp, SYSTR_MSG_EXECVE, &msg) != 0);
+}
+
 /* Prepare to replace arguments */
 
 int
@@ -1348,7 +1384,6 @@
 int
 systrace_fname(struct str_process *strp, caddr_t kdata, size_t len)
 {
-
        if (strp->nfname >= SYSTR_MAXFNAME || len < 2)
                return EINVAL;
 
@@ -1377,9 +1412,10 @@
 systrace_namei(struct nameidata *ndp)
 {
        struct str_process *strp;
-       struct fsystrace *fst;
+       struct fsystrace *fst = NULL; /* XXXGCC */
        struct componentname *cnp = &ndp->ni_cnd;
        size_t i;
+       int hamper = 0;
 
        systrace_lock();
        strp = cnp->cn_proc->p_systrace;
@@ -1388,18 +1424,21 @@
                SYSTRACE_LOCK(fst, curlwp);
                systrace_unlock();
 
-               for (i = 0; i < strp->nfname; i++) {
+               for (i = 0; i < strp->nfname; i++)
                        if (strcmp(cnp->cn_pnbuf, strp->fname[i]) == 0) {
-                               /* ELOOP if namei() tries to readlink */
-                               ndp->ni_loopcnt = MAXSYMLINKS;
-                               cnp->cn_flags &= ~FOLLOW;
-                               cnp->cn_flags |= NOFOLLOW;
+                               hamper = 1;
                                break;
                        }
-               }
                SYSTRACE_UNLOCK(fst, curlwp);
        } else
                systrace_unlock();
+
+       if (hamper) {
+               /* ELOOP if namei() tries to readlink */
+               ndp->ni_loopcnt = MAXSYMLINKS;
+               cnp->cn_flags &= ~FOLLOW;
+               cnp->cn_flags |= NOFOLLOW;
+       }
 }
 
 struct str_process *
@@ -1614,7 +1653,11 @@
        struct str_msgcontainer *cont;
        struct str_message *msg;
        struct fsystrace *fst = strp->parent;
-       int st;
+       int st, pri;
+
+       pri = PWAIT|PCATCH;
+       if (type == SYSTR_MSG_EXECVE)
+               pri &= ~PCATCH;
 
        cont = pool_get(&systr_msgcontainer_pl, PR_WAITOK);
        memset(cont, 0, sizeof(struct str_msgcontainer));
@@ -1651,7 +1694,7 @@
                int f;
                f = curlwp->l_flag & L_SA;
                curlwp->l_flag &= ~L_SA;
-               st = tsleep(strp, PWAIT | PCATCH, "systrmsg", 0);
+               st = tsleep(strp, pri, "systrmsg", 0);
                curlwp->l_flag |= f;
                if (st != 0)
                        return (ERESTART);