[src/trunk]: src/sys Canonicalize the interpreter path in #! scr...

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

details:   https://anonhg.NetBSD.org/src/rev/6b10bb680477
branches:  trunk
changeset: 318514:6b10bb680477
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Apr 27 18:33:24 2018 +0000
description:
Canonicalize the interpreter path in #! scripts since check_exec() expects
an absolute path, and we KASSERT if that's not the case later.

diffstat:

 sys/kern/exec_script.c |  10 ++++------
 sys/kern/kern_exec.c   |  25 ++++++++++++++++---------
 sys/sys/exec.h         |   6 ++++--
 3 files changed, 24 insertions(+), 17 deletions(-)

diffs (125 lines):

diff -r 3e3d4698bb4e -r 6b10bb680477 sys/kern/exec_script.c
--- a/sys/kern/exec_script.c    Fri Apr 27 16:50:56 2018 +0000
+++ b/sys/kern/exec_script.c    Fri Apr 27 18:33:24 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec_script.c,v 1.74 2014/09/05 09:20:59 matt Exp $    */
+/*     $NetBSD: exec_script.c,v 1.75 2018/04/27 18:33:24 christos Exp $        */
 
 /*
  * Copyright (c) 1993, 1994, 1996 Christopher G. Demetriou
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: exec_script.c,v 1.74 2014/09/05 09:20:59 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: exec_script.c,v 1.75 2018/04/27 18:33:24 christos Exp $");
 
 #if defined(SETUIDSCRIPTS) && !defined(FDSCRIPTS)
 #define FDSCRIPTS              /* Need this for safe set-id scripts. */
@@ -280,10 +280,8 @@
        epp->ep_hdrvalid = 0;
 
        /* try loading the interpreter */
-       shell_pathbuf = pathbuf_create(shellname);
-       if (shell_pathbuf == NULL) {
-               error = ENOMEM;
-       } else {
+       if ((error = exec_makepathbuf(l, shellname, UIO_SYSSPACE,
+           &shell_pathbuf, NULL)) == 0) {
                error = check_exec(l, epp, shell_pathbuf);
                pathbuf_destroy(shell_pathbuf);
        }
diff -r 3e3d4698bb4e -r 6b10bb680477 sys/kern/kern_exec.c
--- a/sys/kern/kern_exec.c      Fri Apr 27 16:50:56 2018 +0000
+++ b/sys/kern/kern_exec.c      Fri Apr 27 18:33:24 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_exec.c,v 1.456 2018/02/23 19:43:08 maxv Exp $     */
+/*     $NetBSD: kern_exec.c,v 1.457 2018/04/27 18:33:24 christos Exp $ */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -59,7 +59,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.456 2018/02/23 19:43:08 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.457 2018/04/27 18:33:24 christos Exp $");
 
 #include "opt_exec.h"
 #include "opt_execfmt.h"
@@ -607,9 +607,9 @@
 #endif
 }
 
-static int
-makepathbuf(struct lwp *l, const char *upath, struct pathbuf **pbp,
-    size_t *offs)
+int
+exec_makepathbuf(struct lwp *l, const char *upath, enum uio_seg seg,
+    struct pathbuf **pbp, size_t *offs)
 {
        char *path, *bp;
        size_t len, tlen;
@@ -617,7 +617,11 @@
        struct cwdinfo *cwdi;
 
        path = PNBUF_GET();
-       error = copyinstr(upath, path, MAXPATHLEN, &len);
+       if (seg == UIO_SYSSPACE) {
+               error = copystr(upath, path, MAXPATHLEN, &len);
+       } else {
+               error = copyinstr(upath, path, MAXPATHLEN, &len);
+       }
        if (error) {
                PNBUF_PUT(path);
                DPRINTF(("%s: copyin path @%p %d\n", __func__, upath, error));
@@ -625,7 +629,8 @@
        }
 
        if (path[0] == '/') {
-               *offs = 0;
+               if (offs)
+                       *offs = 0;
                goto out;
        }
 
@@ -651,7 +656,8 @@
 
        memmove(path, bp, tlen);
        path[tlen] = '\0';
-       *offs = tlen - len;
+       if (offs)
+               *offs = tlen - len;
 out:
        *pbp = pathbuf_assimilate(path);
        return 0;
@@ -730,7 +736,8 @@
         * functions call check_exec() recursively - for example,
         * see exec_script_makecmds().
         */
-       if ((error = makepathbuf(l, path, &data->ed_pathbuf, &offs)) != 0)
+       if ((error = exec_makepathbuf(l, path, UIO_USERSPACE,
+           &data->ed_pathbuf, &offs)) != 0)
                goto clrflg;
        data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf);
        data->ed_resolvedpathbuf = PNBUF_GET();
diff -r 3e3d4698bb4e -r 6b10bb680477 sys/sys/exec.h
--- a/sys/sys/exec.h    Fri Apr 27 16:50:56 2018 +0000
+++ b/sys/sys/exec.h    Fri Apr 27 18:33:24 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec.h,v 1.152 2017/11/07 19:44:05 christos Exp $      */
+/*     $NetBSD: exec.h,v 1.153 2018/04/27 18:33:24 christos Exp $      */
 
 /*-
  * Copyright (c) 1992, 1993
@@ -310,7 +310,9 @@
 void   posix_spawn_fa_free(struct posix_spawn_file_actions *, size_t);
 int    do_posix_spawn(struct lwp *, pid_t *, bool*, const char *,
     struct posix_spawn_file_actions *, struct posix_spawnattr *,
-    char *const *argv, char *const *, execve_fetch_element_t);
+    char *const *, char *const *, execve_fetch_element_t);
+int      exec_makepathbuf(struct lwp *, const char *, enum uio_seg,
+    struct pathbuf **, size_t *);
 
 extern int     maxexec;