commit 59357157706d47c365b2227739e17daba3607526 Author: Alessandro Ghedini Date: Sun Mar 1 12:07:45 2015 +0100 Add ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS option This fixes a directory traversal in the cpio tool. Index: libarchive-3.1.2/cpio/bsdcpio.1 =================================================================== --- libarchive-3.1.2.orig/cpio/bsdcpio.1 +++ libarchive-3.1.2/cpio/bsdcpio.1 @@ -156,7 +156,8 @@ See above for description. .It Fl Fl insecure (i and p mode only) Disable security checks during extraction or copying. -This allows extraction via symbolic links and path names containing +This allows extraction via symbolic links, absolute paths, +and path names containing .Sq .. in the name. .It Fl J , Fl Fl xz Index: libarchive-3.1.2/cpio/cpio.c =================================================================== --- libarchive-3.1.2.orig/cpio/cpio.c +++ libarchive-3.1.2/cpio/cpio.c @@ -179,6 +179,7 @@ main(int argc, char *argv[]) cpio->extract_flags |= ARCHIVE_EXTRACT_NO_OVERWRITE_NEWER; cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_SYMLINKS; cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_NODOTDOT; + cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS; cpio->extract_flags |= ARCHIVE_EXTRACT_PERM; cpio->extract_flags |= ARCHIVE_EXTRACT_FFLAGS; cpio->extract_flags |= ARCHIVE_EXTRACT_ACL; @@ -264,6 +265,7 @@ main(int argc, char *argv[]) case OPTION_INSECURE: cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_SYMLINKS; cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NODOTDOT; + cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS; break; case 'L': /* GNU cpio */ cpio->option_follow_links = 1; Index: libarchive-3.1.2/libarchive/archive.h =================================================================== --- libarchive-3.1.2.orig/libarchive/archive.h +++ libarchive-3.1.2/libarchive/archive.h @@ -562,6 +562,8 @@ __LA_DECL int archive_read_set_options(s /* Default: Do not use HFS+ compression if it was not compressed. */ /* This has no effect except on Mac OS v10.6 or later. */ #define ARCHIVE_EXTRACT_HFS_COMPRESSION_FORCED (0x8000) +/* Default: Do not reject entries with absolute paths */ +#define ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS (0x10000) __LA_DECL int archive_read_extract(struct archive *, struct archive_entry *, int flags); Index: libarchive-3.1.2/libarchive/archive_write_disk.3 =================================================================== --- libarchive-3.1.2.orig/libarchive/archive_write_disk.3 +++ libarchive-3.1.2/libarchive/archive_write_disk.3 @@ -177,6 +177,9 @@ The default is to not refuse such paths. Note that paths ending in .Pa .. always cause an error, regardless of this flag. +.It Cm ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS +Refuse to extract an absolute path. +The default is to not refuse such paths. .It Cm ARCHIVE_EXTRACT_SPARSE Scan data for blocks of NUL bytes and try to recreate them with holes. This results in sparse files, independent of whether the archive format Index: libarchive-3.1.2/libarchive/archive_write_disk_posix.c =================================================================== --- libarchive-3.1.2.orig/libarchive/archive_write_disk_posix.c +++ libarchive-3.1.2/libarchive/archive_write_disk_posix.c @@ -2504,8 +2504,9 @@ cleanup_pathname_win(struct archive_writ /* * Canonicalize the pathname. In particular, this strips duplicate * '/' characters, '.' elements, and trailing '/'. It also raises an - * error for an empty path, a trailing '..' or (if _SECURE_NODOTDOT is - * set) any '..' in the path. + * error for an empty path, a trailing '..', (if _SECURE_NODOTDOT is + * set) any '..' in the path or (if ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS + * is set) if the path is absolute. */ static int cleanup_pathname(struct archive_write_disk *a) @@ -2524,8 +2525,15 @@ cleanup_pathname(struct archive_write_di cleanup_pathname_win(a); #endif /* Skip leading '/'. */ - if (*src == '/') + if (*src == '/') { + if (a->flags & ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS) { + archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, + "Path is absolute"); + return (ARCHIVE_FAILED); + } + separator = *src++; + } /* Scan the pathname one element at a time. */ for (;;) { Index: libarchive-3.1.2/libarchive/test/test_write_disk_secure.c =================================================================== --- libarchive-3.1.2.orig/libarchive/test/test_write_disk_secure.c +++ libarchive-3.1.2/libarchive/test/test_write_disk_secure.c @@ -178,6 +178,29 @@ DEFINE_TEST(test_write_disk_secure) assert(S_ISDIR(st.st_mode)); archive_entry_free(ae); + /* + * Without security checks, we should be able to + * extract an absolute path. + */ + assert((ae = archive_entry_new()) != NULL); + archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); + archive_entry_set_mode(ae, S_IFREG | 0777); + assert(0 == archive_write_header(a, ae)); + assert(0 == archive_write_finish_entry(a)); + assertFileExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); + assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp")); + + /* But with security checks enabled, this should fail. */ + assert(archive_entry_clear(ae) != NULL); + archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); + archive_entry_set_mode(ae, S_IFREG | 0777); + archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS); + failure("Extracting an absolute path should fail here."); + assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae)); + archive_entry_free(ae); + assert(0 == archive_write_finish_entry(a)); + assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); + assertEqualInt(ARCHIVE_OK, archive_write_free(a)); /* Test the entries on disk. */