From a84db18fc71d09e801df0ebca048d82e90b32c6a Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 20 Feb 2018 15:57:45 +0100 Subject: tar,unzip: postpone creation of symlinks with "suspicious" targets This mostly reverts commit bc9bbeb2b81001e8731cd2ae501c8fccc8d87cc7 "libarchive: do not extract unsafe symlinks unless $EXTRACT_UNSAFE_SYMLINKS=1" Users report that it is somewhat too restrictive. See https://bugs.busybox.net/show_bug.cgi?id=8411 In particular, this interferes with unpacking of busybox-based filesystems with links like "sbin/applet" -> "../bin/busybox". The change is made smaller by deleting ARCHIVE_EXTRACT_QUIET flag - it is unused since 2010, and removing conditionals on it allows commonalizing some error message codes. function old new delta create_or_remember_symlink - 94 +94 create_symlinks_from_list - 64 +64 tar_main 1002 1006 +4 unzip_main 2732 2724 -8 data_extract_all 984 891 -93 unsafe_symlink_target 147 - -147 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 1/2 up/down: 162/-248) Total: -86 bytes Signed-off-by: Denys Vlasenko --- include/bb_archive.h | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/bb_archive.h b/include/bb_archive.h index 8ed20d7..a5c61e9 100644 --- a/include/bb_archive.h +++ b/include/bb_archive.h @@ -64,6 +64,9 @@ typedef struct archive_handle_t { /* Currently processed file's header */ file_header_t *file_header; + /* List of symlink placeholders */ + llist_t *symlink_placeholders; + /* Process the header component, e.g. tar -t */ void FAST_FUNC (*action_header)(const file_header_t *); @@ -119,15 +122,14 @@ typedef struct archive_handle_t { #define ARCHIVE_RESTORE_DATE (1 << 0) #define ARCHIVE_CREATE_LEADING_DIRS (1 << 1) #define ARCHIVE_UNLINK_OLD (1 << 2) -#define ARCHIVE_EXTRACT_QUIET (1 << 3) -#define ARCHIVE_EXTRACT_NEWER (1 << 4) -#define ARCHIVE_DONT_RESTORE_OWNER (1 << 5) -#define ARCHIVE_DONT_RESTORE_PERM (1 << 6) -#define ARCHIVE_NUMERIC_OWNER (1 << 7) -#define ARCHIVE_O_TRUNC (1 << 8) -#define ARCHIVE_REMEMBER_NAMES (1 << 9) +#define ARCHIVE_EXTRACT_NEWER (1 << 3) +#define ARCHIVE_DONT_RESTORE_OWNER (1 << 4) +#define ARCHIVE_DONT_RESTORE_PERM (1 << 5) +#define ARCHIVE_NUMERIC_OWNER (1 << 6) +#define ARCHIVE_O_TRUNC (1 << 7) +#define ARCHIVE_REMEMBER_NAMES (1 << 8) #if ENABLE_RPM -#define ARCHIVE_REPLACE_VIA_RENAME (1 << 10) +#define ARCHIVE_REPLACE_VIA_RENAME (1 << 9) #endif @@ -197,7 +199,10 @@ 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; -int unsafe_symlink_target(const char *target) FAST_FUNC; +void create_or_remember_symlink(llist_t **symlink_placeholders, + const char *target, + const char *linkname) FAST_FUNC; +void create_symlinks_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; -- cgit v1.1