Author: Raphael Geissert Bug-Debian: https://bugs.debian.org/731860 Description: Avoid directory traversal when extracting archives by skipping over leading slashes and any prefix containing ".." components. Forwarded: yes --- a/lib/decode.c +++ b/lib/decode.c @@ -22,6 +22,36 @@ #endif +char * +safer_name_suffix (char const *file_name) +{ + char const *p, *t; + p = t = file_name; + while (*p == '/') t = ++p; + while (*p) + { + while (p[0] == '.' && p[0] == p[1] && p[2] == '/') + { + p += 3; + t = p; + } + /* advance pointer past the next slash */ + while (*p && (p++)[0] != '/'); + } + + if (!*t) + { + t = "."; + } + + if (t != file_name) + { + /* TODO: warn somehow that the path was modified */ + } + return (char*)t; +} + + /* determine full path name */ char * th_get_pathname(TAR *t) @@ -29,17 +59,17 @@ th_get_pathname(TAR *t) static char filename[MAXPATHLEN]; if (t->th_buf.gnu_longname) - return t->th_buf.gnu_longname; + return safer_name_suffix(t->th_buf.gnu_longname); if (t->th_buf.prefix[0] != '\0') { snprintf(filename, sizeof(filename), "%.155s/%.100s", t->th_buf.prefix, t->th_buf.name); - return filename; + return safer_name_suffix(filename); } snprintf(filename, sizeof(filename), "%.100s", t->th_buf.name); - return filename; + return safer_name_suffix(filename); } --- a/lib/extract.c +++ b/lib/extract.c @@ -298,14 +298,14 @@ tar_extract_hardlink(TAR * t, char *real if (mkdirhier(dirname(filename)) == -1) return -1; libtar_hashptr_reset(&hp); - if (libtar_hash_getkey(t->h, &hp, th_get_linkname(t), + if (libtar_hash_getkey(t->h, &hp, safer_name_suffix(th_get_linkname(t)), (libtar_matchfunc_t)libtar_str_match) != 0) { lnp = (char *)libtar_hashptr_data(&hp); linktgt = &lnp[strlen(lnp) + 1]; } else - linktgt = th_get_linkname(t); + linktgt = safer_name_suffix(th_get_linkname(t)); #ifdef DEBUG printf(" ==> extracting: %s (link to %s)\n", filename, linktgt); @@ -343,9 +343,9 @@ tar_extract_symlink(TAR *t, char *realna #ifdef DEBUG printf(" ==> extracting: %s (symlink to %s)\n", - filename, th_get_linkname(t)); + filename, safer_name_suffix(th_get_linkname(t))); #endif - if (symlink(th_get_linkname(t), filename) == -1) + if (symlink(safer_name_suffix(th_get_linkname(t)), filename) == -1) { #ifdef DEBUG perror("symlink()"); --- a/lib/internal.h +++ b/lib/internal.h @@ -15,3 +15,4 @@ #include +char* safer_name_suffix(char const*); --- a/lib/output.c +++ b/lib/output.c @@ -123,9 +123,9 @@ th_print_long_ls(TAR *t) else printf(" link to "); if ((t->options & TAR_GNU) && t->th_buf.gnu_longlink != NULL) - printf("%s", t->th_buf.gnu_longlink); + printf("%s", safer_name_suffix(t->th_buf.gnu_longlink)); else - printf("%.100s", t->th_buf.linkname); + printf("%.100s", safer_name_suffix(t->th_buf.linkname)); } putchar('\n'); ts/guix.in (augment-load-paths!): Remove use of ~/.config/guix/latest. * build-aux/compile-as-derivation.scm: Replace "/guix/latest/" with "/current/share/guile/site/X.Y" * guix/scripts.scm (warn-about-old-distro)[age]: Check "/current" instead of "/latest". * doc/guix.texi (Invoking guix pull): Document it. * doc/contributing.texi (Running Guix Before It Is Installed): Remove footnote about abusing ~/.config/guix/latest. Ludovic Courtès 2018-01-28guix: Let Emacs detect “scripts/guix.in” appropriate mode....Since commit 6f774d481839f87178c5895ac2d661e141f879b8 which introduces the use of Guile's meta switch in “scripts/guix.in”, Emacs was not using ‘scheme-mode’ for this file. * scripts/guix.in: Replace "-*- scheme -*-" with a local variable. Signed-off-by: Ludovic Courtès <ludo@gnu.org> Mathieu Lirzin 2018-01-23guix: Refactor script....* scripts/guix.in: Remove empty surrounding ‘let’. Define 'main' as the procedure called when running the script. (maybe-augment-load-paths!): Rename to ... (augment-load-paths!): ... this. Use 'and=>' for 'file-exists?'. (run-guix-main): Rename to ... (main): ... this. Call 'augment-load-paths!'. Signed-off-by: Ludovic Courtès <ludo@gnu.org> Mathieu Lirzin 2018-01-23build: Expand ‘scripts/guix’ at Make time....This moves the complexity of Autotools variable expansion outside of the application code. * scripts/guix.in (config-lookup): Delete. (maybe-augment-load-paths!, run-guix-main): Use fully expanded variables instead of calling ‘config-lookup’. * configure.ac: Don't use AC_CONFIG_FILES for ‘scripts/guix’. Use AC_PROG_SED. * Makefile.am (scripts/guix): New rule. (do_subst): New variable. (CLEANFILES, EXTRA_DIST): Adapt. Co-authored-by: Ludovic Courtès <ludo@gnu.org> Mathieu Lirzin