8c24af9dc

Harald van Dijk

2018-05-22

SUCCESS Duration: 145s

Subject

tar: fix interaction of delayed symlink and hardlink creation

No binary (build failed)

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

(log yok)

archival/cpio.c+1 -1

@@ -508,7 +508,7 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
	while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
	continue;

-	create_symlinks_from_list(archive_handle->symlink_placeholders);
+	create_links_from_list(archive_handle->link_placeholders);

	if (archive_handle->cpio__blocks != (off_t)-1
	&& !(opt & OPT_QUIET)

archival/libarchive/data_extract_all.c+7 -9

@@ -122,13 +122,10 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)

	/* Handle hard links separately */
	if (hard_link) {
-	res = link(hard_link, dst_name);
-	if (res != 0) {
-	/* shared message */
-	bb_perror_msg("can't create %slink '%s' to '%s'",
-	"hard", dst_name, hard_link
-	);
-	}
+	create_or_remember_link(&archive_handle->link_placeholders,
+	hard_link,
+	dst_name,
+	1);
	/* Hardlinks have no separate mode/ownership, skip chown/chmod */
	goto ret;
	}
@@ -195,9 +192,10 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
	*
	* Untarring bug.tar would otherwise place evil.py in '/tmp'.
	*/
-	create_or_remember_symlink(&archive_handle->symlink_placeholders,
+	create_or_remember_link(&archive_handle->link_placeholders,
	file_header->link_target,
-	dst_name);
+	dst_name,
+	0);
	break;
	case S_IFSOCK:
	case S_IFBLK:

archival/libarchive/get_header_ar.c+1 -1

@@ -126,7 +126,7 @@ char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
	struct archive_handle_t *sa = archive_handle->dpkg__sub_archive;
	while (archive_handle->dpkg__action_data_subarchive(sa) == EXIT_SUCCESS)
	continue;
-	create_symlinks_from_list(sa->symlink_placeholders);
+	create_links_from_list(sa->link_placeholders);
	} else
	#endif
	archive_handle->action_data(archive_handle);

archival/libarchive/unsafe_symlink_target.c+11 -10

@@ -5,13 +5,14 @@
	#include "libbb.h"
	#include "bb_archive.h"

-	void FAST_FUNC create_or_remember_symlink(llist_t **symlink_placeholders,
+	void FAST_FUNC create_or_remember_link(llist_t **link_placeholders,
	const char *target,
-	const char *linkname)
+	const char *linkname,
+	int hard_link)
	{
-	if (target[0] == '/' \|\| strstr(target, "..")) {
-	llist_add_to(symlink_placeholders,
-	xasprintf("%s%c%s", linkname, '\0', target)
+	if (hard_link \|\| target[0] == '/' \|\| strstr(target, "..")) {
+	llist_add_to_end(link_placeholders,
+	xasprintf("%c%s%c%s", hard_link, linkname, '\0', target)
	);
	return;
	}
@@ -23,17 +24,17 @@ void FAST_FUNC create_or_remember_symlink(llist_t **symlink_placeholders,
	}
	}

-	void FAST_FUNC create_symlinks_from_list(llist_t *list)
+	void FAST_FUNC create_links_from_list(llist_t *list)
	{
	while (list) {
	char *target;

-	target = list->data + strlen(list->data) + 1;
-	if (symlink(target, list->data)) {
+	target = list->data + 1 + strlen(list->data + 1) + 1;
+	if ((*list->data ? link : symlink) (target, list->data + 1)) {
	/* shared message */
	bb_error_msg_and_die("can't create %slink '%s' to '%s'",
-	"sym",
-	list->data, target
+	*list->data ? "hard" : "sym",
+	list->data + 1, target
	);
	}
	list = list->link;

archival/tar.c+1 -1

@@ -1244,7 +1244,7 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
	while (get_header_tar(tar_handle) == EXIT_SUCCESS)
	bb_got_signal = EXIT_SUCCESS; /* saw at least one header, good */

-	create_symlinks_from_list(tar_handle->symlink_placeholders);
+	create_links_from_list(tar_handle->link_placeholders);

	/* Check that every file that should have been extracted was */
	while (tar_handle->accept) {

archival/unzip.c+4 -3

@@ -372,9 +372,10 @@ static void unzip_extract_symlink(llist_t **symlink_placeholders,
	target[xstate.mem_output_size] = '\0';
	#endif
	}
-	create_or_remember_symlink(symlink_placeholders,
+	create_or_remember_link(symlink_placeholders,
	target,
-	dst_fn);
+	dst_fn,
+	0);
	free(target);
	}
	#endif
@@ -990,7 +991,7 @@ int unzip_main(int argc, char **argv)
	}

	#if ENABLE_FEATURE_UNZIP_CDF
-	create_symlinks_from_list(symlink_placeholders);
+	create_links_from_list(symlink_placeholders);
	#endif

	if ((opts & OPT_l) && quiet <= 1) {

include/bb_archive.h+6 -5

@@ -64,8 +64,8 @@ typedef struct archive_handle_t {
	/* Currently processed file's header */
	file_header_t *file_header;

-	/* List of symlink placeholders */
-	llist_t *symlink_placeholders;
+	/* List of link placeholders */
+	llist_t *link_placeholders;

	/* Process the header component, e.g. tar -t */
	void FAST_FUNC (action_header)(const file_header_t );
@@ -203,10 +203,11 @@ void seek_by_jump(int fd, off_t amount) FAST_FUNC;
	void seek_by_read(int fd, off_t amount) FAST_FUNC;

	const char strip_unsafe_prefix(const char str) FAST_FUNC;
-	void create_or_remember_symlink(llist_t **symlink_placeholders,
+	void create_or_remember_link(llist_t **link_placeholders,
	const char *target,
-	const char *linkname) FAST_FUNC;
-	void create_symlinks_from_list(llist_t *list) FAST_FUNC;
+	const char *linkname,
+	int hard_link) FAST_FUNC;
+	void create_links_from_list(llist_t *list) FAST_FUNC;

	void data_align(archive_handle_t *archive_handle, unsigned boundary) FAST_FUNC;
	const llist_t find_list_entry(const llist_t list, const char *filename) FAST_FUNC;

testsuite/tar.tests+16 -0

@@ -365,4 +365,20 @@ n8fYaKlioCTzL2oXYczyUUIP4u5IpwoSEwWdtoA=
	SKIP=
	cd .. \|\| exit 1; rm -rf tar.tempdir 2>/dev/null

+	mkdir tar.tempdir && cd tar.tempdir \|\| exit 1
+	testing "Symlinks and hardlinks coexist" '\
+	mkdir dir
+	>dir/a
+	ln -s ../dir/a dir/b
+	ln dir/b dir/c
+	mkdir new
+	tar cf - dir/* \| tar -C new -xvf - 2>&1
+	' "\
+	dir/a
+	dir/b
+	dir/c
+	" \
+	"" ""
+	cd .. \|\| exit 1; rm -rf tar.tempdir 2>/dev/null
+
	exit $FAILCOUNT