Re: [PATCH] rsync: Patch CVE-2022-29154

[Michael Tremer <michael.tremer@ipfire.org>]

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Reviewed-by: Michael Tremer <michael.tremer(a)ipfire.org>

Thank you.

> On 5 Aug 2022, at 13:00, Peter Müller <peter.mueller(a)ipfire.org> wrote:
> 
> https://www.openwall.com/lists/oss-security/2022/08/02/1
> 
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> ---
> lfs/rsync                              |   5 +-
> src/patches/rsync-CVE-2022-29154.patch | 322 +++++++++++++++++++++++++
> 2 files changed, 326 insertions(+), 1 deletion(-)
> create mode 100644 src/patches/rsync-CVE-2022-29154.patch
> 
> diff --git a/lfs/rsync b/lfs/rsync
> index f40c28ce2..c27258929 100644
> --- a/lfs/rsync
> +++ b/lfs/rsync
> @@ -34,7 +34,7 @@ DL_FROM    = $(URL_IPFIRE)
> DIR_APP    = $(DIR_SRC)/$(THISAPP)
> TARGET     = $(DIR_INFO)/$(THISAPP)
> PROG       = rsync
> -PAK_VER    = 14
> +PAK_VER    = 15
> 
> DEPS       =
> 
> @@ -85,6 +85,9 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
> 	# Replace shebang in rsync-ssl
> 	cd $(DIR_APP) && sed -i -e "s@^#!.*@#!/bin/bash@" rsync-ssl
> 
> +	# Fix for CVE-2022-29154
> +	cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/rsync-CVE-2022-29154.patch
> +
> 	cd $(DIR_APP) && ./configure \
> 	--prefix=/usr \
> 	--without-included-popt \
> diff --git a/src/patches/rsync-CVE-2022-29154.patch b/src/patches/rsync-CVE-2022-29154.patch
> new file mode 100644
> index 000000000..d3b4499a4
> --- /dev/null
> +++ b/src/patches/rsync-CVE-2022-29154.patch
> @@ -0,0 +1,322 @@
> +commit b7231c7d02cfb65d291af74ff66e7d8c507ee871
> +Author: Wayne Davison <wayne(a)opencoder.net>
> +Date:   Sun Jul 31 16:55:34 2022 -0700
> +
> +    Some extra file-list safety checks.
> +
> +diff --git a/exclude.c b/exclude.c
> +index 39073a0c..b670c8ba 100644
> +--- 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 *listp, const char *pat, unsigned int pat_
> + 	}
> + }
> + 
> ++/* 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 logcode code, char const *name,
> + 			      : 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 char **rulestr_ptr,
> + 		}
> + 		switch (ch) {
> + 		case ':':
> ++			trust_sender_filter = 1;
> + 			rule->rflags |= FILTRULE_PERDIR_MERGE
> + 				      | FILTRULE_FINISH_SETUP;
> + 			/* FALL THROUGH */
> +diff --git a/flist.c b/flist.c
> +index 1ba306bc..0e6bf782 100644
> +--- 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_entry(int f, struct file_list *flist, int x
> + 		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 */
> +diff --git a/io.c b/io.c
> +index cf94cee7..a6e3ed30 100644
> +--- 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++;
> + 			}
> +diff --git a/main.c b/main.c
> +index 58920a2d..5a7fbdd7 100644
> +--- 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 *machine, char *user, char **remote_argv, in
> + #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 *argv[])
> + 		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 *argv[])
> + 			if (!rsync_port && !*arg) /* Turn an empty arg into a dot dir. */
> + 				arg = ".";
> + 			remote_argv[i] = arg;
> ++			add_implied_include(arg);
> + 		}
> + 	}
> + 
> +diff --git a/receiver.c b/receiver.c
> +index b3a69da0..93cf8efd 100644
> +--- a/receiver.c
> ++++ b/receiver.c
> +@@ -593,10 +593,13 @@ int recv_files(int f_in, int f_out, char *local_name)
> + 		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
> -- 
> 2.35.3