Description: CVE-2015-1197 Apply patch by Vitezslav Cizek of SuSE to fix CVE-2015-1197. Upstream is dormant or no longer existing. To restore the old behaviour use --extract-over-symlinks (Closes: #774669) This issue has been discovered by Alexander Cherepanov. Author: Vitezslav Cizek Bug-Debian: https://bugs.debian.org/774669 Upstream-Status: Backport Signed-off-by: Robert Yang --- cpio-2.11+dfsg.orig/doc/cpio.1 +++ cpio-2.11+dfsg/doc/cpio.1 @@ -22,6 +22,7 @@ cpio \- copy files to and from archives [\-\-owner=[user][:.][group]] [\-\-no-preserve-owner] [\-\-message=message] [\-\-force\-local] [\-\-no\-absolute\-filenames] [\-\-sparse] [\-\-only\-verify\-crc] [\-\-to\-stdout] [\-\-quiet] [\-\-rsh-command=command] +[\-\-extract\-over\-symlinks] [\-\-help] [\-\-version] [pattern...] [< archive] .B cpio --- cpio-2.11+dfsg.orig/src/copyin.c +++ cpio-2.11+dfsg/src/copyin.c @@ -700,6 +700,51 @@ copyin_link (struct cpio_file_stat *file free (link_name); } + +static int +path_contains_symlink(char *path) +{ + struct stat st; + char *slash; + char *nextslash; + + /* we got NULL pointer or empty string */ + if (!path || !*path) { + return false; + } + + slash = path; + + while ((nextslash = strchr(slash + 1, '/')) != NULL) { + slash = nextslash; + *slash = '\0'; + + if (lstat(path, &st) != 0) { + if (errno == ELOOP) { + /* ELOOP - too many symlinks */ + *slash = '/'; + return true; + } else if (errno == ENOMEM) { + /* No memory for lstat - terminate */ + xalloc_die(); + } else { + /* cannot lstat path - give up */ + *slash = '/'; + return false; + } + } + + if (S_ISLNK(st.st_mode)) { + *slash = '/'; + return true; + } + + *slash = '/'; + } + + return false; +} + static void copyin_file (struct cpio_file_stat *file_hdr, int in_file_des) { @@ -1471,6 +1516,23 @@ process_copy_in () { /* Copy the input file into the directory structure. */ + /* Can we write files over symlinks? */ + if (!extract_over_symlinks) + { + if (path_contains_symlink(file_hdr.c_name)) + { + /* skip the file */ + /* + fprintf(stderr, "Can't write over symlinks. Skipping %s\n", file_hdr.c_name); + tape_toss_input (in_file_des, file_hdr.c_filesize); + tape_skip_padding (in_file_des, file_hdr.c_filesize); + continue; + */ + /* terminate */ + error (1, 0, _("Can't write over symlinks: %s\n"), file_hdr.c_name); + } + } + /* Do we need to rename the file? */ if (rename_flag || rename_batch_file) { --- cpio-2.11+dfsg.orig/src/extern.h +++ cpio-2.11+dfsg/src/extern.h @@ -95,6 +95,7 @@ extern char input_is_special; extern char output_is_special; extern char input_is_seekable; extern char output_is_seekable; +extern bool extract_over_symlinks; extern int (*xstat) (); extern void (*copy_function) (); --- cpio-2.11+dfsg.orig/src/global.c +++ cpio-2.11+dfsg/src/global.c @@ -187,6 +187,9 @@ bool to_stdout_option = false; /* The name this program was run with. */ char *program_name; +/* Extract files over symbolic links */ +bool extract_over_symlinks; + /* A pointer to either lstat or stat, depending on whether dereferencing of symlinks is done for input files. */ int (*xstat) (); --- cpio-2.11+dfsg.orig/src/main.c +++ cpio-2.11+dfsg/src/main.c @@ -57,7 +57,8 @@ enum cpio_options { FORCE_LOCAL_OPTION, DEBUG_OPTION, BLOCK_SIZE_OPTION, - TO_STDOUT_OPTION + TO_STDOUT_OPTION, + EXTRACT_OVER_SYMLINKS }; const char *program_authors[] = @@ -222,6 +223,8 @@ static struct argp_option options[] = { N_("Create leading directories where needed"), GRID+1 }, {"no-preserve-owner", NO_PRESERVE_OWNER_OPTION, 0, 0, N_("Do not change the ownership of the files"), GRID+1 }, + {"extract-over-symlinks", EXTRACT_OVER_SYMLINKS, 0, 0, + N_("Force writing over symbolic links"), GRID+1 }, {"unconditional", 'u', NULL, 0, N_("Replace all files unconditionally"), GRID+1 }, {"sparse", SPARSE_OPTION, NULL, 0, @@ -412,6 +415,10 @@ crc newc odc bin ustar tar (all-caps als no_chown_flag = true; break; + case EXTRACT_OVER_SYMLINKS: /* --extract-over-symlinks */ + extract_over_symlinks = true; + break; + case 'o': /* Copy-out mode. */ if (copy_function != 0) error (PAXEXIT_FAILURE, 0, _("Mode already defined"));