--- /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-contrib.git / commitdiff
