+++ /dev/null
-From b7231c7d02cfb65d291af74ff66e7d8c507ee871 Mon Sep 17 00:00:00 2001
-From: Wayne Davison <wayne@opencoder.net>
-Date: Sun, 31 Jul 2022 16:55:34 -0700
-Subject: [PATCH] Some extra file-list safety checks.
-
-Upstream-Status: Backport [https://github.com/WayneD/rsync/commit/b7231c7d02cfb65d291af74ff66e7d8c507ee871]
-CVE: CVE-2022-29154
-Signed-off-by: Khem Raj <raj.khem@gmail.com>
----
- exclude.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
- flist.c | 17 ++++++-
- io.c | 4 ++
- main.c | 7 ++-
- receiver.c | 11 +++--
- rsync.1.md | 44 ++++++++++++++++--
- 6 files changed, 202 insertions(+), 11 deletions(-)
-
---- a/exclude.c
-+++ b/exclude.c
-@@ -27,16 +27,22 @@ extern int am_server;
- extern int am_sender;
- extern int eol_nulls;
- extern int io_error;
-+extern int xfer_dirs;
-+extern int recurse;
- extern int local_server;
- extern int prune_empty_dirs;
- extern int ignore_perishable;
-+extern int old_style_args;
-+extern int relative_paths;
- extern int delete_mode;
- extern int delete_excluded;
- extern int cvs_exclude;
- extern int sanitize_paths;
- extern int protocol_version;
-+extern int list_only;
- extern int module_id;
-
-+extern char *filesfrom_host;
- extern char curr_dir[MAXPATHLEN];
- extern unsigned int curr_dir_len;
- extern unsigned int module_dirlen;
-@@ -44,8 +50,10 @@ extern unsigned int module_dirlen;
- filter_rule_list filter_list = { .debug_type = "" };
- filter_rule_list cvs_filter_list = { .debug_type = " [global CVS]" };
- filter_rule_list daemon_filter_list = { .debug_type = " [daemon]" };
-+filter_rule_list implied_filter_list = { .debug_type = " [implied]" };
-
- int saw_xattr_filter = 0;
-+int trust_sender_filter = 0;
-
- /* Need room enough for ":MODS " prefix plus some room to grow. */
- #define MAX_RULE_PREFIX (16)
-@@ -292,6 +300,125 @@ static void add_rule(filter_rule_list *l
- }
- }
-
-+/* Each arg the client sends to the remote sender turns into an implied include
-+ * that the receiver uses to validate the file list from the sender. */
-+void add_implied_include(const char *arg)
-+{
-+ filter_rule *rule;
-+ int arg_len, saw_wild = 0, backslash_cnt = 0;
-+ int slash_cnt = 1; /* We know we're adding a leading slash. */
-+ const char *cp;
-+ char *p;
-+ if (old_style_args || list_only || filesfrom_host != NULL)
-+ return;
-+ if (relative_paths) {
-+ cp = strstr(arg, "/./");
-+ if (cp)
-+ arg = cp+3;
-+ } else {
-+ if ((cp = strrchr(arg, '/')) != NULL)
-+ arg = cp + 1;
-+ }
-+ arg_len = strlen(arg);
-+ if (arg_len) {
-+ if (strpbrk(arg, "*[?")) {
-+ /* We need to add room to escape backslashes if wildcard chars are present. */
-+ cp = arg;
-+ while ((cp = strchr(cp, '\\')) != NULL) {
-+ arg_len++;
-+ cp++;
-+ }
-+ saw_wild = 1;
-+ }
-+ arg_len++; /* Leave room for the prefixed slash */
-+ rule = new0(filter_rule);
-+ if (!implied_filter_list.head)
-+ implied_filter_list.head = implied_filter_list.tail = rule;
-+ else {
-+ rule->next = implied_filter_list.head;
-+ implied_filter_list.head = rule;
-+ }
-+ rule->rflags = FILTRULE_INCLUDE + (saw_wild ? FILTRULE_WILD : 0);
-+ p = rule->pattern = new_array(char, arg_len + 1);
-+ *p++ = '/';
-+ cp = arg;
-+ while (*cp) {
-+ switch (*cp) {
-+ case '\\':
-+ backslash_cnt++;
-+ if (saw_wild)
-+ *p++ = '\\';
-+ *p++ = *cp++;
-+ break;
-+ case '/':
-+ if (p[-1] == '/') /* This is safe because of the initial slash. */
-+ break;
-+ if (relative_paths) {
-+ filter_rule const *ent;
-+ int found = 0;
-+ *p = '\0';
-+ for (ent = implied_filter_list.head; ent; ent = ent->next) {
-+ if (ent != rule && strcmp(ent->pattern, rule->pattern) == 0)
-+ found = 1;
-+ }
-+ if (!found) {
-+ filter_rule *R_rule = new0(filter_rule);
-+ R_rule->rflags = FILTRULE_INCLUDE + (saw_wild ? FILTRULE_WILD : 0);
-+ R_rule->pattern = strdup(rule->pattern);
-+ R_rule->u.slash_cnt = slash_cnt;
-+ R_rule->next = implied_filter_list.head;
-+ implied_filter_list.head = R_rule;
-+ }
-+ }
-+ slash_cnt++;
-+ *p++ = *cp++;
-+ break;
-+ default:
-+ *p++ = *cp++;
-+ break;
-+ }
-+ }
-+ *p = '\0';
-+ rule->u.slash_cnt = slash_cnt;
-+ arg = (const char *)rule->pattern;
-+ }
-+
-+ if (recurse || xfer_dirs) {
-+ /* Now create a rule with an added "/" & "**" or "*" at the end */
-+ rule = new0(filter_rule);
-+ if (recurse)
-+ rule->rflags = FILTRULE_INCLUDE | FILTRULE_WILD | FILTRULE_WILD2;
-+ else
-+ rule->rflags = FILTRULE_INCLUDE | FILTRULE_WILD;
-+ /* A +4 in the len leaves enough room for / * * \0 or / * \0 \0 */
-+ if (!saw_wild && backslash_cnt) {
-+ /* We are appending a wildcard, so now the backslashes need to be escaped. */
-+ p = rule->pattern = new_array(char, arg_len + backslash_cnt + 3 + 1);
-+ cp = arg;
-+ while (*cp) {
-+ if (*cp == '\\')
-+ *p++ = '\\';
-+ *p++ = *cp++;
-+ }
-+ } else {
-+ p = rule->pattern = new_array(char, arg_len + 3 + 1);
-+ if (arg_len) {
-+ memcpy(p, arg, arg_len);
-+ p += arg_len;
-+ }
-+ }
-+ if (p[-1] != '/')
-+ *p++ = '/';
-+ *p++ = '*';
-+ if (recurse)
-+ *p++ = '*';
-+ *p = '\0';
-+ rule->u.slash_cnt = slash_cnt + 1;
-+ rule->next = implied_filter_list.head;
-+ implied_filter_list.head = rule;
-+ }
-+}
-+
- /* This frees any non-inherited items, leaving just inherited items on the list. */
- static void pop_filter_list(filter_rule_list *listp)
- {
-@@ -718,7 +845,7 @@ static void report_filter_result(enum lo
- : name_flags & NAME_IS_DIR ? "directory"
- : "file";
- rprintf(code, "[%s] %sing %s %s because of pattern %s%s%s\n",
-- w, actions[*w!='s'][!(ent->rflags & FILTRULE_INCLUDE)],
-+ w, actions[*w=='g'][!(ent->rflags & FILTRULE_INCLUDE)],
- t, name, ent->pattern,
- ent->rflags & FILTRULE_DIRECTORY ? "/" : "", type);
- }
-@@ -890,6 +1017,7 @@ static filter_rule *parse_rule_tok(const
- }
- switch (ch) {
- case ':':
-+ trust_sender_filter = 1;
- rule->rflags |= FILTRULE_PERDIR_MERGE
- | FILTRULE_FINISH_SETUP;
- /* FALL THROUGH */
---- a/flist.c
-+++ b/flist.c
-@@ -73,6 +73,7 @@ extern int need_unsorted_flist;
- extern int sender_symlink_iconv;
- extern int output_needs_newline;
- extern int sender_keeps_checksum;
-+extern int trust_sender_filter;
- extern int unsort_ndx;
- extern uid_t our_uid;
- extern struct stats stats;
-@@ -83,8 +84,7 @@ extern char curr_dir[MAXPATHLEN];
-
- extern struct chmod_mode_struct *chmod_modes;
-
--extern filter_rule_list filter_list;
--extern filter_rule_list daemon_filter_list;
-+extern filter_rule_list filter_list, implied_filter_list, daemon_filter_list;
-
- #ifdef ICONV_OPTION
- extern int filesfrom_convert;
-@@ -986,6 +986,19 @@ static struct file_struct *recv_file_ent
- exit_cleanup(RERR_UNSUPPORTED);
- }
-
-+ if (*thisname != '.' || thisname[1] != '\0') {
-+ int filt_flags = S_ISDIR(mode) ? NAME_IS_DIR : NAME_IS_FILE;
-+ if (!trust_sender_filter /* a per-dir filter rule means we must trust the sender's filtering */
-+ && filter_list.head && check_filter(&filter_list, FINFO, thisname, filt_flags) < 0) {
-+ rprintf(FERROR, "ERROR: rejecting excluded file-list name: %s\n", thisname);
-+ exit_cleanup(RERR_PROTOCOL);
-+ }
-+ if (implied_filter_list.head && check_filter(&implied_filter_list, FINFO, thisname, filt_flags) <= 0) {
-+ rprintf(FERROR, "ERROR: rejecting unrequested file-list name: %s\n", thisname);
-+ exit_cleanup(RERR_PROTOCOL);
-+ }
-+ }
-+
- if (inc_recurse && S_ISDIR(mode)) {
- if (one_file_system) {
- /* Room to save the dir's device for -x */
---- a/io.c
-+++ b/io.c
-@@ -419,6 +419,7 @@ static void forward_filesfrom_data(void)
- while (s != eob) {
- if (*s++ == '\0') {
- ff_xb.len = s - sob - 1;
-+ add_implied_include(sob);
- if (iconvbufs(ic_send, &ff_xb, &iobuf.out, flags) < 0)
- exit_cleanup(RERR_PROTOCOL); /* impossible? */
- write_buf(iobuf.out_fd, s-1, 1); /* Send the '\0'. */
-@@ -450,9 +451,12 @@ static void forward_filesfrom_data(void)
- char *f = ff_xb.buf + ff_xb.pos;
- char *t = ff_xb.buf;
- char *eob = f + len;
-+ char *cur = t;
- /* Eliminate any multi-'\0' runs. */
- while (f != eob) {
- if (!(*t++ = *f++)) {
-+ add_implied_include(cur);
-+ cur = t;
- while (f != eob && *f == '\0')
- f++;
- }
---- a/main.c
-+++ b/main.c
-@@ -89,6 +89,7 @@ extern int backup_dir_len;
- extern int basis_dir_cnt;
- extern int default_af_hint;
- extern int stdout_format_has_i;
-+extern int trust_sender_filter;
- extern struct stats stats;
- extern char *stdout_format;
- extern char *logfile_format;
-@@ -104,7 +105,7 @@ extern char curr_dir[MAXPATHLEN];
- extern char backup_dir_buf[MAXPATHLEN];
- extern char *basis_dir[MAX_BASIS_DIRS+1];
- extern struct file_list *first_flist;
--extern filter_rule_list daemon_filter_list;
-+extern filter_rule_list daemon_filter_list, implied_filter_list;
-
- uid_t our_uid;
- gid_t our_gid;
-@@ -635,6 +636,7 @@ static pid_t do_cmd(char *cmd, char *mac
- #ifdef ICONV_CONST
- setup_iconv();
- #endif
-+ trust_sender_filter = 1;
- } else if (local_server) {
- /* If the user didn't request --[no-]whole-file, force
- * it on, but only if we're not batch processing. */
-@@ -1500,6 +1502,8 @@ static int start_client(int argc, char *
- char *dummy_host;
- int dummy_port = rsync_port;
- int i;
-+ if (filesfrom_fd < 0)
-+ add_implied_include(remote_argv[0]);
- /* For remote source, any extra source args must have either
- * the same hostname or an empty hostname. */
- for (i = 1; i < remote_argc; i++) {
-@@ -1523,6 +1527,7 @@ static int start_client(int argc, char *
- if (!rsync_port && !*arg) /* Turn an empty arg into a dot dir. */
- arg = ".";
- remote_argv[i] = arg;
-+ add_implied_include(arg);
- }
- }
-
---- a/receiver.c
-+++ b/receiver.c
-@@ -593,10 +593,13 @@ int recv_files(int f_in, int f_out, char
- if (DEBUG_GTE(RECV, 1))
- rprintf(FINFO, "recv_files(%s)\n", fname);
-
-- if (daemon_filter_list.head && (*fname != '.' || fname[1] != '\0')
-- && check_filter(&daemon_filter_list, FLOG, fname, 0) < 0) {
-- rprintf(FERROR, "attempt to hack rsync failed.\n");
-- exit_cleanup(RERR_PROTOCOL);
-+ if (daemon_filter_list.head && (*fname != '.' || fname[1] != '\0')) {
-+ int filt_flags = S_ISDIR(file->mode) ? NAME_IS_DIR : NAME_IS_FILE;
-+ if (check_filter(&daemon_filter_list, FLOG, fname, filt_flags) < 0) {
-+ rprintf(FERROR, "ERROR: rejecting file transfer request for daemon excluded file: %s\n",
-+ fname);
-+ exit_cleanup(RERR_PROTOCOL);
-+ }
- }
-
- #ifdef SUPPORT_XATTRS
---- a/rsync.1.md
-+++ b/rsync.1.md
-@@ -154,6 +154,33 @@ rsync daemon by leaving off the module n
-
- See the following section for more details.
-
-+## MULTI-HOST SECURITY
-+
-+Rsync takes steps to ensure that the file requests that are shared in a
-+transfer are protected against various security issues. Most of the potential
-+problems arise on the receiving side where rsync takes steps to ensure that the
-+list of files being transferred remains within the bounds of what was
-+requested.
-+
-+Toward this end, rsync 3.1.2 and later have aborted when a file list contains
-+an absolute or relative path that tries to escape out of the top of the
-+transfer. Also, beginning with version 3.2.5, rsync does two more safety
-+checks of the file list to (1) ensure that no extra source arguments were added
-+into the transfer other than those that the client requested and (2) ensure
-+that the file list obeys the exclude rules that we sent to the sender.
-+
-+For those that don't yet have a 3.2.5 client rsync, it is safest to do a copy
-+into a dedicated destination directory for the remote files rather than
-+requesting the remote content get mixed in with other local content. For
-+example, doing an rsync copy into your home directory is potentially unsafe on
-+an older rsync if the remote rsync is being controlled by a bad actor:
-+
-+> rsync -aiv host1:dir1 ~
-+
-+A safer command would be:
-+
-+> rsync -aiv host1:dir1 ~/host1-files
-+
- ## ADVANCED USAGE
-
- The syntax for requesting multiple files from a remote host is done by
-@@ -2323,6 +2350,12 @@ your home directory (remove the '=' for
- behavior. The environment is always overridden by manually specified
- positive or negative options (the negative is `--no-old-args`).
-
-+ Note that this option also disables the extra safety check added in 3.2.5
-+ that ensures that a remote sender isn't including extra top-level items in
-+ the file-list that you didn't request. This side-effect is necessary
-+ because we can't know for sure what names to expect when the remote shell
-+ is interpreting the args.
-+
- This option conflicts with the [`--protect-args`](#opt) option.
-
- 0. `--protect-args`, `-s`
projects / thirdparty / openembedded / openembedded-core.git / commitdiff
