diff options
Diffstat (limited to '0008-rsync-protocol.patch')
-rw-r--r-- | 0008-rsync-protocol.patch | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/0008-rsync-protocol.patch b/0008-rsync-protocol.patch new file mode 100644 index 000000000000..e1694ee0adc3 --- /dev/null +++ b/0008-rsync-protocol.patch @@ -0,0 +1,130 @@ +From: Russ Allbery <rra@stanford.edu> +Subject: [PATCH] Handle the rsync v3 -e option for protocol information + +As of rsync 3, rsync reused the -e option to pass protocol information +from the client to the server. We therefore cannot reject all -e +options to rsync, only ones not sent with --server or containing +something other than protocol information as an argument. + +Also scan the rsync command line for any --rsh option and reject it as +well. This replaces and improves the upstream strategy for rejecting +that command-line option, taking advantage of the parsing added to +check the -e option. + +Based on work by Robert Hardy. + +Debian Bug#471803 + +Signed-off-by: Russ Allbery <rra@stanford.edu> + +--- + util.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++------- + 1 file changed, 72 insertions(+), 8 deletions(-) + +diff --git a/util.c b/util.c +index f98d2bc..a257b06 100644 +--- a/util.c ++++ b/util.c +@@ -56,6 +56,7 @@ + #ifdef HAVE_LIBGEN_H + #include <libgen.h> + #endif /* HAVE_LIBGEN_H */ ++#include <regex.h> + + /* LOCAL INCLUDES */ + #include "pathnames.h" +@@ -198,6 +199,73 @@ bool check_command( char *cl, ShellOptions_t *opts, char *cmd, int cmdflag ) + + + /* ++ * rsync_e_okay() - take the command line passed to rssh and look for an -e ++ * option. If one is found, make sure --server is provided ++ * and the option contains only the protocol information. ++ * Also check for and reject any --rsh option. Returns FALSE ++ * if the command line should not be allowed, TRUE if it is ++ * okay. ++ */ ++static int rsync_e_okay( char **vec ) ++{ ++ regex_t re; ++ int server = FALSE; ++ int e_found = FALSE; ++ ++ /* ++ * rsync will send -e, followed by either just "." (meaning no special ++ * protocol) or "N.N" (meaning a pre-release protocol version), ++ * followed by some number of alphabetic flags indicating various ++ * supported options. There may be other options between - and the e, ++ * but -e will always be the last option in the string. A typical ++ * option passed by the client is "-ltpre.iL". ++ * ++ * Note that if --server is given, this should never be parsed as a ++ * shell, but we'll tightly verify it anyway, just in case. ++ * ++ * This regex matches the acceptable flags containing -e, so if it ++ * does not match, the command line should be rejected. ++ */ ++ static const char pattern[] ++ = "^-[a-df-zA-Z]*e[0-9]*\\.[0-9]*[a-zA-Z]*$"; ++ ++ /* ++ * Only recognize --server if it's the first option. rsync itself ++ * always passes it that way, and if it's not the first argument, it ++ * could be hidden from the server as an argument to some other ++ * option. ++ */ ++ if ( vec && vec[0] && vec[1] && strcmp(vec[1], "--server") == 0 ){ ++ server = TRUE; ++ } ++ ++ /* Check the remaining options for -e or --rsh. */ ++ if ( regcomp(&re, pattern, REG_EXTENDED | REG_NOSUB) != 0 ){ ++ return FALSE; ++ } ++ while (vec && *vec){ ++ if ( strcmp(*vec, "--") == 0 ) break; ++ if ( strcmp(*vec, "--rsh") == 0 ++ || strncmp(*vec, "--rsh=", strlen("--rsh=")) == 0 ){ ++ regfree(&re); ++ return FALSE; ++ } ++ if ( strncmp(*vec, "--", 2) != 0 && opt_exist(*vec, 'e') ){ ++ e_found = TRUE; ++ if ( regexec(&re, *vec, 0, NULL, 0) != 0 ){ ++ regfree(&re); ++ return FALSE; ++ } ++ } ++ vec++; ++ } ++ regfree(&re); ++ if ( e_found && !server ) return FALSE; ++ return TRUE; ++} ++ ++ ++/* + * check_command_line() - take the command line passed to rssh, and verify + * that the specified command is one the user is + * allowed to run and validate the arguments. Return the +@@ -230,14 +298,10 @@ char *check_command_line( char **cl, ShellOptions_t *opts ) + + if ( check_command(*cl, opts, PATH_RSYNC, RSSH_ALLOW_RSYNC) ){ + /* filter -e option */ +- if ( opt_filter(cl, 'e') ) return NULL; +- while (cl && *cl){ +- if ( strstr(*cl, "--rsh" ) ){ +- fprintf(stderr, "\ninsecure --rsh= not allowed."); +- log_msg("insecure --rsh option in rsync command line!"); +- return NULL; +- } +- cl++; ++ if ( !rsync_e_okay(cl) ){ ++ fprintf(stderr, "\ninsecure -e or --rsh option not allowed."); ++ log_msg("insecure -e or --rsh option in rsync command line!"); ++ return NULL; + } + return PATH_RSYNC; + } +-- +tg: (f8b36e2..) fixes/rsync-protocol (depends on: upstream) |