Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

make the checkok test stricter to avoid races, and use O_REGULAR.

This commit is contained in:
christos 2017-11-10 16:35:54 +00:00
parent e6cc4be609
commit 7c6c19a729
1 changed files with 13 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
external/bsd/nvi/dist/common/recover.c vendored
View File

@ -1,4 +1,4 @@
/* $NetBSD: recover.c,v 1.9 2017/11/04 14:20:12 christos Exp $ */
/* $NetBSD: recover.c,v 1.10 2017/11/10 16:35:54 christos Exp $ */
/*-
* Copyright (c) 1993, 1994
* The Regents of the University of California. All rights reserved.
@ -16,7 +16,7 @@
static const char sccsid[] = "Id: recover.c,v 10.31 2001/11/01 15:24:44 skimo Exp (Berkeley) Date: 2001/11/01 15:24:44 ";
#endif /* not lint */
#else
__RCSID("$NetBSD: recover.c,v 1.9 2017/11/04 14:20:12 christos Exp $");
__RCSID("$NetBSD: recover.c,v 1.10 2017/11/10 16:35:54 christos Exp $");
#endif
#include <sys/param.h>
@ -121,6 +121,10 @@ static char *rcv_gets(char *, size_t, int);
static int rcv_mailfile(SCR *, int, char *);
static int rcv_mktemp(SCR *, char *, const char *, int);
#ifndef O_REGULAR
#define O_REGULAR O_NONBLOCK
#endif
/*
* rcv_tmp --
* Build a file name that will be used as the recovery file.
@ -487,14 +491,19 @@ err: if (!issync)
* This is simpler than checking for getuid() == st.st_uid and we want
* to preserve the functionality that root can recover anything which
* means that root should know better and be careful.
*
* Checking the mode is racy though (someone can chmod between the
* open and the stat call, so also check for uid match or root.
*/
static int
checkok(int fd)
{
struct stat sb;
uid_t uid = getuid();
return fstat(fd, &sb) != -1 && S_ISREG(sb.st_mode) &&
(sb.st_mode & (S_IRWXG|S_IRWXO)) == 0;
(sb.st_mode & (S_IRWXG|S_IRWXO)) == 0 &&
(uid == 0 || uid == sb.st_uid);
}
/*
@ -659,7 +668,7 @@ rcv_read(SCR *sp, FREF *frp)
* if we're using fcntl(2), there's no way to lock a file
* descriptor that's not open for writing.
*/
if ((fd = open(recpath, O_RDWR|O_NONBLOCK|O_NOFOLLOW|O_CLOEXEC,
if ((fd = open(recpath, O_RDWR|O_REGULAR|O_NOFOLLOW|O_CLOEXEC,
0)) == -1)
continue;