X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/e8fd2c45ddd6f59f159baaa2c154ced5ce36f3df..1d28cc061677bd07d9bed48dd84bd5c590247043:/src/src/transports/appendfile.c diff --git a/src/src/transports/appendfile.c b/src/src/transports/appendfile.c index cc1d6333c..c39c07c9f 100644 --- a/src/src/transports/appendfile.c +++ b/src/src/transports/appendfile.c @@ -2,9 +2,10 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2018 */ -/* Copyright (c) The Exim maintainers 2020 */ +/* Copyright (c) The Exim maintainers 2020 - 2022 */ +/* Copyright (c) University of Cambridge 1995 - 2020 */ /* See the file NOTICE for conditions of use and distribution. */ +/* SPDX-License-Identifier: GPL-2.0-or-later */ #include "../exim.h" @@ -112,70 +113,27 @@ BOOL appendfile_transport_entry(transport_instance *tblock, address_item *addr) /* Default private options block for the appendfile transport. */ appendfile_transport_options_block appendfile_transport_option_defaults = { - NULL, /* filename */ - NULL, /* dirname */ - US"q${base62:$tod_epoch}-$inode", /* dirfilename */ - NULL, /* message_prefix (default reset in init if not bsmtp) */ - NULL, /* message_suffix (ditto) */ - US"anywhere", /* create_file_string (string value for create_file) */ - NULL, /* quota */ - NULL, /* quota_directory */ - NULL, /* quota_filecount */ - NULL, /* quota_size_regex */ - NULL, /* quota_warn_threshold */ - NULL, /* mailbox_size_string */ - NULL, /* mailbox_filecount_string */ - NULL, /* expand_maildir_use_size_file */ - US"^(?:cur|new|\\..*)$", /* maildir_dir_regex */ - NULL, /* maildir_tag */ - NULL, /* maildirfolder_create_regex */ - NULL, /* mailstore_prefix */ - NULL, /* mailstore_suffix */ - NULL, /* check_string (default changed for non-bsmtp file)*/ - NULL, /* escape_string (ditto) */ - NULL, /* file_format */ - 0, /* quota_value */ - 0, /* quota_warn_threshold_value */ - -1, /* mailbox_size_value */ - -1, /* mailbox_filecount_value */ - 0, /* quota_filecount_value */ - APPENDFILE_MODE, /* mode */ - APPENDFILE_DIRECTORY_MODE, /* dirmode */ - APPENDFILE_LOCKFILE_MODE, /* lockfile_mode */ - 30*60, /* lockfile_timeout */ - 0, /* lock_fcntl_timeout */ - 0, /* lock_flock_timeout */ - 10, /* lock_retries */ - 3, /* lock_interval */ - 10, /* maildir_retries */ - create_anywhere,/* create_file */ - 0, /* options */ - FALSE, /* allow_fifo */ - FALSE, /* allow_symlink */ - FALSE, /* check_group */ - TRUE, /* check_owner */ - TRUE, /* create_directory */ - FALSE, /* notify_comsat */ - TRUE, /* use_lockfile */ - FALSE, /* set_use_lockfile */ - TRUE, /* use_fcntl */ - FALSE, /* set_use_fcntl */ - FALSE, /* use_flock */ - FALSE, /* set_use_flock */ - FALSE, /* use_mbx_lock */ - FALSE, /* set_use_mbx_lock */ - FALSE, /* use_bsmtp */ - FALSE, /* use_crlf */ - FALSE, /* file_must_exist */ - TRUE, /* mode_fail_narrower */ - FALSE, /* maildir_format */ - FALSE, /* maildir_use_size_file */ - FALSE, /* mailstore_format */ - FALSE, /* mbx_format */ - FALSE, /* quota_warn_threshold_is_percent */ - TRUE, /* quota_is_inclusive */ - FALSE, /* quota_no_check */ - FALSE /* quota_filecount_no_check */ + /* all non-mentioned members zero/null/false */ + .dirfilename = US"q${base62:$tod_epoch}-$inode", + .create_file_string = US"anywhere", + .maildir_dir_regex = US"^(?:cur|new|\\..*)$", + .mailbox_size_value = -1, + .mailbox_filecount_value = -1, + .mode = APPENDFILE_MODE, + .dirmode = APPENDFILE_DIRECTORY_MODE, + .lockfile_mode = APPENDFILE_LOCKFILE_MODE, + .lockfile_timeout = 30*60, + .lock_retries = 10, + .lock_interval = 3, + .maildir_retries = 10, + .create_file = create_anywhere, + .check_owner = TRUE, + .create_directory = TRUE, + .notify_comsat = FALSE, + .use_lockfile = TRUE, + .use_fcntl = TRUE, + .mode_fail_narrower = TRUE, + .quota_is_inclusive = TRUE, }; @@ -235,17 +193,15 @@ mailbox_filecount */ for (int i = 0; i < 5; i++) { - double d; + double d = default_value; int no_check = 0; uschar *which = NULL; - if (q == NULL) d = default_value; - else + if (q) { - uschar *rest; - uschar *s = expand_string(q); + uschar * rest, * s; - if (!s) + if (!(s = expand_string(q))) { *errmsg = string_sprintf("Expansion of \"%s\" in %s transport failed: " "%s", q, tblock->name, expand_string_message); @@ -315,8 +271,8 @@ for (int i = 0; i < 5; i++) break; case 2: - if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4) - which = US"quota_warn_threshold"; + if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4) + which = US"quota_warn_threshold"; ob->quota_warn_threshold_value = (off_t)d; q = ob->mailbox_size_string; default_value = -1.0; @@ -362,6 +318,7 @@ appendfile_transport_init(transport_instance *tblock) { appendfile_transport_options_block *ob = (appendfile_transport_options_block *)(tblock->options_block); +uschar * s; /* Set up the setup entry point, to be called in the privileged state */ @@ -460,20 +417,17 @@ if (tblock->uid_set && !tblock->gid_set && !tblock->expand_gid) /* If "create_file" is set, check that a valid option is given, and set the integer variable. */ -if (ob->create_file_string) +if ((s = ob->create_file_string ) && *s) { - int value = 0; - if (Ustrcmp(ob->create_file_string, "anywhere") == 0) - value = create_anywhere; - else if (Ustrcmp(ob->create_file_string, "belowhome") == 0) - value = create_belowhome; - else if (Ustrcmp(ob->create_file_string, "inhome") == 0) - value = create_inhome; + int val = 0; + if (Ustrcmp(s, "anywhere") == 0) val = create_anywhere; + else if (*s == '/' || Ustrcmp(s, "belowhome") == 0) val = create_belowhome; + else if (Ustrcmp(s, "inhome") == 0) val = create_inhome; else log_write(0, LOG_PANIC_DIE|LOG_CONFIG, - "invalid value given for \"file_create\" for the %s transport: %s", - tblock->name, ob->create_file_string); - ob->create_file = value; + "invalid value given for \"create_file\" for the %s transport: '%s'", + tblock->name, s); + ob->create_file = val; } /* If quota_warn_threshold is set, set up default for warn_message. It may @@ -698,14 +652,14 @@ the log, because we are running as an unprivileged user here. Arguments: dirname the name of the directory countptr where to add the file count (because this function recurses) - regex a compiled regex to get the size from a name + re a compiled regex to get the size from a name Returns: the sum of the sizes of the stattable files zero if the directory cannot be opened */ off_t -check_dir_size(const uschar * dirname, int *countptr, const pcre *regex) +check_dir_size(const uschar * dirname, int * countptr, const pcre2_code * re) { DIR *dir; off_t sum = 0; @@ -724,22 +678,28 @@ for (struct dirent *ent; ent = readdir(dir); ) /* If there's a regex, try to find the size using it */ - if (regex) + if (re) { - int ovector[6]; - if (pcre_exec(regex, NULL, CS name, Ustrlen(name), 0, 0, ovector,6) >= 2) + pcre2_match_data * md = pcre2_match_data_create(2, pcre_gen_ctx); + int rc = pcre2_match(re, (PCRE2_SPTR)name, PCRE2_ZERO_TERMINATED, + 0, 0, md, pcre_gen_mtc_ctx); + PCRE2_SIZE * ovec = pcre2_get_ovector_pointer(md); + if ( rc >= 0 + && (rc = pcre2_get_ovector_count(md)) >= 2) { uschar *endptr; - off_t size = (off_t)Ustrtod(name + ovector[2], &endptr); - if (endptr == name + ovector[3]) + off_t size = (off_t)Ustrtod(name + ovec[2], &endptr); + if (endptr == name + ovec[3]) { sum += size; DEBUG(D_transport) debug_printf("check_dir_size: size from %s is " OFF_T_FMT "\n", name, size); + /* pcre2_match_data_free(md); gen ctx needs no free */ continue; } } + /* pcre2_match_data_free(md); gen ctx needs no free */ DEBUG(D_transport) debug_printf("check_dir_size: regex did not match %s\n", name); } @@ -758,7 +718,7 @@ for (struct dirent *ent; ent = readdir(dir); ) if ((statbuf.st_mode & S_IFMT) == S_IFREG) sum += statbuf.st_size / statbuf.st_nlink; else if ((statbuf.st_mode & S_IFMT) == S_IFDIR) - sum += check_dir_size(path, &count, regex); + sum += check_dir_size(path, &count, re); } closedir(dir); @@ -936,28 +896,28 @@ we can't do any tests. Arguments: filename the file name create_file the ob->create_file option + deliver_dir the delivery directory Returns: TRUE if creation is permitted */ static BOOL -check_creation(uschar *filename, int create_file) +check_creation(uschar *filename, int create_file, const uschar * deliver_dir) { BOOL yield = TRUE; -if (deliver_home && create_file != create_anywhere) +if (deliver_dir && create_file != create_anywhere) { - int len = Ustrlen(deliver_home); + int len = Ustrlen(deliver_dir); uschar *file = filename; while (file[0] == '/' && file[1] == '/') file++; - if (Ustrncmp(file, deliver_home, len) != 0 || file[len] != '/' || - ( Ustrchr(file+len+2, '/') != NULL && - ( - create_file != create_belowhome || - Ustrstr(file+len, "/../") != NULL - ) - ) + if ( Ustrncmp(file, deliver_dir, len) != 0 + || file[len] != '/' + || Ustrchr(file+len+2, '/') != NULL + && ( create_file != create_belowhome + || Ustrstr(file+len, "/../") != NULL + ) ) yield = FALSE; /* If yield is TRUE, the file name starts with the home directory, and does @@ -995,10 +955,10 @@ if (deliver_home && create_file != create_anywhere) if (rp) { uschar hdbuffer[PATH_MAX+1]; - uschar *rph = deliver_home; + const uschar * rph = deliver_dir; int rlen = Ustrlen(big_buffer); - if ((rp = US realpath(CS deliver_home, CS hdbuffer))) + if ((rp = US realpath(CS deliver_dir, CS hdbuffer))) { rph = hdbuffer; len = Ustrlen(rph); @@ -1009,7 +969,7 @@ if (deliver_home && create_file != create_anywhere) { yield = FALSE; DEBUG(D_transport) debug_printf("Real path \"%s\" does not match \"%s\"\n", - big_buffer, deliver_home); + big_buffer, deliver_dir); } } } @@ -1179,6 +1139,7 @@ appendfile_transport_entry( appendfile_transport_options_block *ob = (appendfile_transport_options_block *)(tblock->options_block); struct stat statbuf; +const uschar * deliver_dir; uschar *fdname = NULL; uschar *filename = NULL; uschar *hitchname = NULL; @@ -1282,12 +1243,6 @@ if (!(path = expand_string(fdname))) expand_string_message); goto ret_panic; } -if (is_tainted(path)) - { - addr->message = string_sprintf("Tainted '%s' (file or directory " - "name for %s transport) not permitted", path, tblock->name); - goto ret_panic; - } if (path[0] != '/') { @@ -1364,6 +1319,12 @@ if (f.dont_deliver) return FALSE; } +/* If an absolute path was given for create_file the it overrides deliver_home +(here) and de-taints the filename (below, after check_creation() */ + +deliver_dir = *ob->create_file_string == '/' + ? ob->create_file_string : deliver_home; + /* Handle the case of a file name. If the file name is /dev/null, we can save ourselves some effort and just give a success return right away. */ @@ -1380,10 +1341,20 @@ if (!isdirectory) } /* Set the name of the file to be opened, and the file to which the data - is written, and find out if we are permitted to create a non-existent file. */ + is written, and find out if we are permitted to create a non-existent file. + If the create_file option is an absolute path and the file was within it, + de-taint. Chaeck for a tainted path. */ + if ( (allow_creation_here = check_creation(path, ob->create_file, deliver_dir)) + && ob->create_file == create_belowhome) + if (is_tainted(path)) + { + DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path); + path = string_copy_taint(path, GET_UNTAINTED); + } + + if (is_tainted(path)) goto tainted_ret_panic; dataname = filename = path; - allow_creation_here = check_creation(filename, ob->create_file); /* If ob->create_directory is set, attempt to create the directories in which this mailbox lives, but only if we are permitted to create the file @@ -1393,17 +1364,16 @@ if (!isdirectory) if (ob->create_directory && allow_creation_here) { uschar *p = Ustrrchr(path, '/'); - *p = '\0'; - if (!directory_make(NULL, path, ob->dirmode, FALSE)) + p = string_copyn(path, p - path); + if (!directory_make(NULL, p, ob->dirmode, FALSE)) { addr->basic_errno = errno; addr->message = string_sprintf("failed to create directories for %s: %s", path, - strerror(errno)); + exim_errstr(errno)); DEBUG(D_transport) debug_printf("%s transport: %s\n", tblock->name, path); return FALSE; } - *p = '/'; } /* If file_format is set we must check that any existing file matches one of @@ -1780,7 +1750,7 @@ if (!isdirectory) { addr->basic_errno = ERRNO_NOTREGULAR; addr->message = string_sprintf("mailbox %s%s has too many links (%lu)", - filename, islink ? " (symlink)" : "", (ulong)statbuf.st_nlink); + filename, islink ? " (symlink)" : "", (unsigned long)statbuf.st_nlink); goto RETURN; } @@ -2200,10 +2170,11 @@ scanning is expensive; for maildirs some fudges have been invented: else { - uschar *check_path = path; /* Default quota check path */ - const pcre *regex = NULL; /* Regex for file size from file name */ + uschar *check_path; /* Default quota check path */ + const pcre2_code * re = NULL; /* Regex for file size from file name */ - if (!check_creation(string_sprintf("%s/any", path), ob->create_file)) + if (!check_creation(string_sprintf("%s/any", path), + ob->create_file, deliver_dir)) { addr->basic_errno = ERRNO_BADCREATE; addr->message = string_sprintf("tried to create file in %s, but " @@ -2211,6 +2182,20 @@ else goto RETURN; } + /* If the create_file option is an absolute path and the file was within + it, de-taint. Otherwise check for taint. */ + + if (is_tainted(path)) + if (ob->create_file == create_belowhome) + { + DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path); + path = string_copy_taint(path, GET_UNTAINTED); + } + else + goto tainted_ret_panic; + + check_path = path; + #ifdef SUPPORT_MAILDIR /* For a maildir delivery, ensure that all the relevant directories exist, and a maildirfolder file if necessary. */ @@ -2229,21 +2214,14 @@ else if (ob->quota_value > 0 || THRESHOLD_CHECK || ob->maildir_use_size_file) { - const uschar *error; - int offset; - /* Compile the regex if there is one. */ if (ob->quota_size_regex) { - if (!(regex = pcre_compile(CS ob->quota_size_regex, PCRE_COPT, - CCSS &error, &offset, NULL))) - { - addr->message = string_sprintf("appendfile: regular expression " - "error: %s at offset %d while compiling %s", error, offset, - ob->quota_size_regex); + if (!(re = regex_compile(ob->quota_size_regex, + MCS_NOFLAGS, &addr->message, pcre_gen_cmp_ctx))) return FALSE; - } + DEBUG(D_transport) debug_printf("using regex for file sizes: %s\n", ob->quota_size_regex); } @@ -2315,22 +2293,15 @@ else #ifdef SUPPORT_MAILDIR if (ob->maildir_use_size_file) { - const pcre *dir_regex = NULL; - const uschar *error; - int offset; + const pcre2_code * dir_regex = NULL; if (ob->maildir_dir_regex) { int check_path_len = Ustrlen(check_path); - if (!(dir_regex = pcre_compile(CS ob->maildir_dir_regex, PCRE_COPT, - CCSS &error, &offset, NULL))) - { - addr->message = string_sprintf("appendfile: regular expression " - "error: %s at offset %d while compiling %s", error, offset, - ob->maildir_dir_regex); + if (!(dir_regex = regex_compile(ob->maildir_dir_regex, + MCS_NOFLAGS, &addr->message, pcre_gen_cmp_ctx))) return FALSE; - } DEBUG(D_transport) debug_printf("using regex for maildir directory selection: %s\n", @@ -2346,7 +2317,7 @@ else uschar *s = path + check_path_len; while (*s == '/') s++; s = *s ? string_sprintf("%s/new", s) : US"new"; - if (pcre_exec(dir_regex, NULL, CS s, Ustrlen(s), 0, 0, NULL, 0) < 0) + if (!regex_match(dir_regex, s, -1, NULL)) { disable_quota = TRUE; DEBUG(D_transport) debug_printf("delivery directory does not match " @@ -2367,7 +2338,7 @@ else off_t size; int filecount; - if ((maildirsize_fd = maildir_ensure_sizefile(check_path, ob, regex, dir_regex, + if ((maildirsize_fd = maildir_ensure_sizefile(check_path, ob, re, dir_regex, &size, &filecount)) == -1) { addr->basic_errno = errno; @@ -2392,7 +2363,7 @@ else * (void)unlink(CS string_sprintf("%s/maildirsize", check_path)); * if (THRESHOLD_CHECK) * mailbox_size = maildir_compute_size(check_path, &mailbox_filecount, &old_latest, - * regex, dir_regex, FALSE); + * re, dir_regex, FALSE); * } */ @@ -2414,7 +2385,7 @@ else int filecount = 0; DEBUG(D_transport) debug_printf("quota checks on directory %s\n", check_path); - size = check_dir_size(check_path, &filecount, regex); + size = check_dir_size(check_path, &filecount, re); if (mailbox_size < 0) mailbox_size = size; if (mailbox_filecount < 0) mailbox_filecount = filecount; } @@ -3205,7 +3176,7 @@ else uschar *iptr = expand_string(nametag); if (iptr) { - uschar *etag = store_get(Ustrlen(iptr) + 2, is_tainted(iptr)); + uschar *etag = store_get(Ustrlen(iptr) + 2, iptr); uschar *optr = etag; for ( ; *iptr; iptr++) if (mac_isgraph(*iptr) && *iptr != '/') @@ -3319,6 +3290,9 @@ put in the first address of a batch. */ return FALSE; +tainted_ret_panic: + addr->message = string_sprintf("Tainted '%s' (file or directory " + "name for %s transport) not permitted", path, tblock->name); ret_panic: addr->transport_return = PANIC; return FALSE;