forked from mirrors/nixpkgs
144 lines
5.9 KiB
Diff
144 lines
5.9 KiB
Diff
From 59357157706d47c365b2227739e17daba3607526 Mon Sep 17 00:00:00 2001
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From: Alessandro Ghedini <alessandro@ghedini.me>
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Date: Sun, 1 Mar 2015 12:07:45 +0100
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Subject: [PATCH] Add ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS option
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This fixes a directory traversal in the cpio tool.
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---
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cpio/bsdcpio.1 | 3 ++-
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cpio/cpio.c | 2 ++
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libarchive/archive.h | 2 ++
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libarchive/archive_write_disk.3 | 3 +++
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libarchive/archive_write_disk_posix.c | 14 +++++++++++---
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libarchive/test/test_write_disk_secure.c | 23 +++++++++++++++++++++++
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6 files changed, 43 insertions(+), 4 deletions(-)
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diff --git a/cpio/bsdcpio.1 b/cpio/bsdcpio.1
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index f966aa0..e52546e 100644
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--- a/cpio/bsdcpio.1
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+++ b/cpio/bsdcpio.1
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@@ -156,7 +156,8 @@ See above for description.
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.It Fl Fl insecure
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(i and p mode only)
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Disable security checks during extraction or copying.
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-This allows extraction via symbolic links and path names containing
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+This allows extraction via symbolic links, absolute paths,
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+and path names containing
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.Sq ..
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in the name.
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.It Fl J , Fl Fl xz
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diff --git a/cpio/cpio.c b/cpio/cpio.c
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index 0acde11..b267e9b 100644
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--- a/cpio/cpio.c
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+++ b/cpio/cpio.c
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@@ -171,6 +171,7 @@ main(int argc, char *argv[])
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cpio->extract_flags |= ARCHIVE_EXTRACT_NO_OVERWRITE_NEWER;
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cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_SYMLINKS;
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cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_NODOTDOT;
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+ cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS;
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cpio->extract_flags |= ARCHIVE_EXTRACT_PERM;
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cpio->extract_flags |= ARCHIVE_EXTRACT_FFLAGS;
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cpio->extract_flags |= ARCHIVE_EXTRACT_ACL;
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@@ -256,6 +257,7 @@ main(int argc, char *argv[])
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case OPTION_INSECURE:
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cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_SYMLINKS;
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cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NODOTDOT;
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+ cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS;
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break;
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case 'L': /* GNU cpio */
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cpio->option_follow_links = 1;
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diff --git a/libarchive/archive.h b/libarchive/archive.h
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index 1f0fc38..ef635ac 100644
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--- a/libarchive/archive.h
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+++ b/libarchive/archive.h
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@@ -649,6 +649,8 @@ __LA_DECL int archive_read_set_passphrase_callback(struct archive *,
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/* Default: Do not use HFS+ compression if it was not compressed. */
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/* This has no effect except on Mac OS v10.6 or later. */
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#define ARCHIVE_EXTRACT_HFS_COMPRESSION_FORCED (0x8000)
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+/* Default: Do not reject entries with absolute paths */
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+#define ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS (0x10000)
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__LA_DECL int archive_read_extract(struct archive *, struct archive_entry *,
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int flags);
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diff --git a/libarchive/archive_write_disk.3 b/libarchive/archive_write_disk.3
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index fa925cc..a2e7afa 100644
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--- a/libarchive/archive_write_disk.3
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+++ b/libarchive/archive_write_disk.3
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@@ -177,6 +177,9 @@ The default is to not refuse such paths.
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Note that paths ending in
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.Pa ..
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always cause an error, regardless of this flag.
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+.It Cm ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS
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+Refuse to extract an absolute path.
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+The default is to not refuse such paths.
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.It Cm ARCHIVE_EXTRACT_SPARSE
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Scan data for blocks of NUL bytes and try to recreate them with holes.
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This results in sparse files, independent of whether the archive format
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diff --git a/libarchive/archive_write_disk_posix.c b/libarchive/archive_write_disk_posix.c
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index ab3bdac..c1290eb 100644
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--- a/libarchive/archive_write_disk_posix.c
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+++ b/libarchive/archive_write_disk_posix.c
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@@ -2509,8 +2509,9 @@ cleanup_pathname_win(struct archive_write_disk *a)
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/*
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* Canonicalize the pathname. In particular, this strips duplicate
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* '/' characters, '.' elements, and trailing '/'. It also raises an
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- * error for an empty path, a trailing '..' or (if _SECURE_NODOTDOT is
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- * set) any '..' in the path.
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+ * error for an empty path, a trailing '..', (if _SECURE_NODOTDOT is
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+ * set) any '..' in the path or (if ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS
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+ * is set) if the path is absolute.
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*/
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static int
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cleanup_pathname(struct archive_write_disk *a)
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@@ -2529,8 +2530,15 @@ cleanup_pathname(struct archive_write_disk *a)
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cleanup_pathname_win(a);
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#endif
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/* Skip leading '/'. */
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- if (*src == '/')
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+ if (*src == '/') {
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+ if (a->flags & ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS) {
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+ archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
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+ "Path is absolute");
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+ return (ARCHIVE_FAILED);
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+ }
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+
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separator = *src++;
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+ }
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/* Scan the pathname one element at a time. */
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for (;;) {
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diff --git a/libarchive/test/test_write_disk_secure.c b/libarchive/test/test_write_disk_secure.c
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index 31c5bfd..2c94206 100644
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--- a/libarchive/test/test_write_disk_secure.c
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+++ b/libarchive/test/test_write_disk_secure.c
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@@ -178,6 +178,29 @@ DEFINE_TEST(test_write_disk_secure)
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assert(S_ISDIR(st.st_mode));
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archive_entry_free(ae);
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+ /*
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+ * Without security checks, we should be able to
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+ * extract an absolute path.
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+ */
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+ assert((ae = archive_entry_new()) != NULL);
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+ archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
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+ archive_entry_set_mode(ae, S_IFREG | 0777);
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+ assert(0 == archive_write_header(a, ae));
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+ assert(0 == archive_write_finish_entry(a));
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+ assertFileExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
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+ assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"));
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+
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+ /* But with security checks enabled, this should fail. */
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+ assert(archive_entry_clear(ae) != NULL);
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+ archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
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+ archive_entry_set_mode(ae, S_IFREG | 0777);
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+ archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS);
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+ failure("Extracting an absolute path should fail here.");
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+ assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
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+ archive_entry_free(ae);
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+ assert(0 == archive_write_finish_entry(a));
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+ assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
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+
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assertEqualInt(ARCHIVE_OK, archive_write_free(a));
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/* Test the entries on disk. */
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