rpms/tar
7
0
Fork 0
Code Issues Pull Requests Releases Activity
c8
tar/SOURCES/tar-1.30-Fix-the-no-overwrite-dir-option
CentOS Sources b5d40a243a import tar-1.30-9.el8
2023-05-17 03:14:00 +00:00

298 lines
9.8 KiB
Plaintext
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

From 14d8fc718f0c872274b90991ee634b0cd8e1a6f0 Mon Sep 17 00:00:00 2001
From: Sergey Poznyakoff <gray@gnu.org>
Date: Sat, 8 Feb 2020 13:01:47 +0200
Subject: [PATCH] Fix the --no-overwrite-dir option
Given this option, tar failed to preserve permissions of empty directories
and to create files under directories owned by the current user that did
not have the S_IWUSR bit set.
* src/extract.c (fd_chmod): Rename to fd_i_chmod.
(fd_chmod): New function.
(safe_dir_mode): New function.
(extract_dir): Special handling for existing directories in
--no-overwrite-dir mode.
* tests/extrac23.at: New file.
* tests/Makefile.am: Add new test case.
* tests/testsuite.at: Likewise.
---
src/extract.c | 128 ++++++++++++++++++++++++++++++---------------
tests/Makefile.am | 1 +
tests/extrac23.at | 58 ++++++++++++++++++++
tests/testsuite.at | 1 +
4 files changed, 146 insertions(+), 42 deletions(-)
create mode 100644 tests/extrac23.at
diff --git a/src/extract.c b/src/extract.c
index a4a35a57..5a38ba70 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -194,7 +194,7 @@ extr_init (void)
/* Use fchmod if possible, fchmodat otherwise. */
static int
-fd_chmod (int fd, char const *file, mode_t mode, int atflag)
+fd_i_chmod (int fd, char const *file, mode_t mode, int atflag)
{
if (0 <= fd)
{
@@ -205,6 +205,42 @@ fd_chmod (int fd, char const *file, mode_t mode, int atflag)
return fchmodat (chdir_fd, file, mode, atflag);
}
+/* A version of fd_i_chmod which gracefully handles several common error
+ conditions. Additional argument TYPEFLAG is the type of file in tar
+ notation.
+ */
+static int
+fd_chmod(int fd, char const *file_name, int mode, int atflag, int typeflag)
+{
+ int chmod_errno = fd_i_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
+
+ /* On Solaris, chmod may fail if we don't have PRIV_ALL, because
+ setuid-root files would otherwise be a backdoor. See
+ http://opensolaris.org/jive/thread.jspa?threadID=95826
+ (2009-09-03). */
+ if (chmod_errno == EPERM && (mode & S_ISUID)
+ && priv_set_restore_linkdir () == 0)
+ {
+ chmod_errno = fd_i_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
+ priv_set_remove_linkdir ();
+ }
+
+ /* Linux fchmodat does not support AT_SYMLINK_NOFOLLOW, and
+ returns ENOTSUP even when operating on non-symlinks, try
+ again with the flag disabled if it does not appear to be
+ supported and if the file is not a symlink. This
+ introduces a race, alas. */
+ if (atflag && typeflag != SYMTYPE && ! implemented (chmod_errno))
+ chmod_errno = fd_i_chmod (fd, file_name, mode, 0) == 0 ? 0 : errno;
+
+ if (chmod_errno && (typeflag != SYMTYPE || implemented (chmod_errno)))
+ {
+ errno = chmod_errno;
+ return -1;
+ }
+ return 0;
+}
+
/* Use fchown if possible, fchownat otherwise. */
static int
fd_chown (int fd, char const *file, uid_t uid, gid_t gid, int atflag)
@@ -259,35 +295,8 @@ set_mode (char const *file_name,
if (current_mode != mode)
{
- int chmod_errno =
- fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
-
- /* On Solaris, chmod may fail if we don't have PRIV_ALL, because
- setuid-root files would otherwise be a backdoor. See
- http://opensolaris.org/jive/thread.jspa?threadID=95826
- (2009-09-03). */
- if (chmod_errno == EPERM && (mode & S_ISUID)
- && priv_set_restore_linkdir () == 0)
- {
- chmod_errno =
- fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno;
- priv_set_remove_linkdir ();
- }
-
- /* Linux fchmodat does not support AT_SYMLINK_NOFOLLOW, and
- returns ENOTSUP even when operating on non-symlinks, try
- again with the flag disabled if it does not appear to be
- supported and if the file is not a symlink. This
- introduces a race, alas. */
- if (atflag && typeflag != SYMTYPE && ! implemented (chmod_errno))
- chmod_errno = fd_chmod (fd, file_name, mode, 0) == 0 ? 0 : errno;
-
- if (chmod_errno
- && (typeflag != SYMTYPE || implemented (chmod_errno)))
- {
- errno = chmod_errno;
- chmod_error_details (file_name, mode);
- }
+ if (fd_chmod (fd, file_name, mode, atflag, typeflag))
+ chmod_error_details (file_name, mode);
}
}
}
@@ -975,6 +984,26 @@ is_directory_link (const char *file_name)
return res;
}
+/* Given struct stat of a directory (or directory member) whose ownership
+ or permissions of will be restored later, return the temporary permissions
+ for that directory, sufficiently restrictive so that in the meantime
+ processes owned by other users do not inadvertently create files under this
+ directory that inherit the wrong owner, group, or permissions from the
+ directory.
+
+ If not root, though, make the directory writeable and searchable at first,
+ so that files can be created under it.
+*/
+static inline int
+safe_dir_mode (struct stat const *st)
+{
+ return ((st->st_mode
+ & (0 < same_owner_option || 0 < same_permissions_option
+ ? S_IRWXU
+ : MODE_RWX))
+ | (we_are_root ? 0 : MODE_WXUSR));
+}
+
/* Extractor functions for various member types */
static int
@@ -1004,18 +1033,7 @@ extract_dir (char *file_name, int typeflag)
else if (typeflag == GNUTYPE_DUMPDIR)
skip_member ();
- /* If ownership or permissions will be restored later, create the
- directory with restrictive permissions at first, so that in the
- meantime processes owned by other users do not inadvertently
- create files under this directory that inherit the wrong owner,
- group, or permissions from the directory. If not root, though,
- make the directory writeable and searchable at first, so that
- files can be created under it. */
- mode = ((current_stat_info.stat.st_mode
- & (0 < same_owner_option || 0 < same_permissions_option
- ? S_IRWXU
- : MODE_RWX))
- | (we_are_root ? 0 : MODE_WXUSR));
+ mode = safe_dir_mode (&current_stat_info.stat);
for (;;)
{
@@ -1031,6 +1049,7 @@ extract_dir (char *file_name, int typeflag)
if (errno == EEXIST
&& (interdir_made
|| keep_directory_symlink_option
+ || old_files_option == NO_OVERWRITE_DIR_OLD_FILES
|| old_files_option == DEFAULT_OLD_FILES
|| old_files_option == OVERWRITE_OLD_FILES))
{
@@ -1051,6 +1070,31 @@ extract_dir (char *file_name, int typeflag)
repair_delayed_set_stat (file_name, &st);
return 0;
}
+ else if (old_files_option == NO_OVERWRITE_DIR_OLD_FILES)
+ {
+ /* Temporarily change the directory mode to a safe
+ value, to be able to create files in it, should
+ the need be.
+ */
+ mode = safe_dir_mode (&st);
+ status = fd_chmod(-1, file_name, mode,
+ AT_SYMLINK_NOFOLLOW, DIRTYPE);
+ if (status == 0)
+ {
+ /* Store the actual directory mode, to be restored
+ later.
+ */
+ current_stat_info.stat = st;
+ current_mode = mode & ~ current_umask;
+ current_mode_mask = MODE_RWX;
+ atflag = AT_SYMLINK_NOFOLLOW;
+ break;
+ }
+ else
+ {
+ chmod_error_details (file_name, mode);
+ }
+ }
break;
}
}
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0369a950..31ae3460 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -121,6 +121,7 @@ TESTSUITE_AT = \
extrac19.at\
extrac20.at\
extrac21.at\
+ extrac23.at\
filerem01.at\
filerem02.at\
dirrem01.at\
diff --git a/tests/extrac23.at b/tests/extrac23.at
new file mode 100644
index 00000000..669d18b6
--- /dev/null
+++ b/tests/extrac23.at
@@ -0,0 +1,58 @@
+# Test suite for GNU tar. -*- Autotest -*-
+# Copyright 2020 Free Software Foundation, Inc.
+#
+# This file is part of GNU tar.
+#
+# GNU tar is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# GNU tar is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+AT_SETUP([--no-overwrite-dir])
+AT_KEYWORDS([extract extrac23 no-overwrite-dir])
+
+# Description: Implementation of the --no-overwrite-dir option was flawed in
+# tar versions up to 1.32.90. This option is intended to preserve metadata
+# of existing directories. In fact it worked only for non-empty directories.
+# Moreover, if the actual directory was owned by the user tar runs as and the
+# S_IWUSR bit was not set in its actual permissions, tar failed to create files
+# in it.
+#
+# Reported by: Michael Kaufmann <mail@michael-kaufmann.ch>
+# References: <20200207112934.Horde.anXzYhAj2CHiwUrw5CuT0G-@webmail.michael-kaufmann.ch>,
+# https://lists.gnu.org/archive/html/bug-tar/2020-02/msg00003.html
+
+AT_TAR_CHECK([
+# Test if the directory permissions are restored properly.
+mkdir dir
+chmod 755 dir
+tar cf a.tar dir
+chmod 777 dir
+tar -xf a.tar --no-overwrite-dir
+genfile --stat=mode.777 dir
+
+# Test if temprorary permissions are set correctly to allow the owner
+# to write to the directory.
+genfile --file dir/file
+tar cf a.tar dir
+rm dir/file
+chmod 400 dir
+tar -xf a.tar --no-overwrite-dir
+genfile --stat=mode.777 dir
+chmod 700 dir
+find dir
+],
+[0],
+[777
+400
+dir
+dir/file
+])
+AT_CLEANUP
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 2cc43a19..0620a3c7 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -343,6 +343,7 @@ m4_include([extrac19.at])
m4_include([extrac19.at])
m4_include([extrac20.at])
m4_include([extrac21.at])
+m4_include([extrac23.at])
m4_include([backup01.at])
--
2.37.3
Reference in New Issue View Git Blame Copy Permalink