The branch master has been updated via 8a585601fea1091022034dd14b961c1ecd5916c3 (commit) from a3b0d466930ec45bc3ddf4c9e853d73d37783f44 (commit)
- Log ----------------------------------------------------------------- commit 8a585601fea1091022034dd14b961c1ecd5916c3 Author: Matt Caswell <m...@openssl.org> Date: Fri Mar 10 10:51:35 2017 +0000 Fix out-of-memory condition in conf conf has the ability to expand variables in config files. Repeatedly doing this can lead to an exponential increase in the amount of memory required. This places a limit on the length of a value that can result from an expansion. Credit to OSS-Fuzz for finding this problem. Reviewed-by: Rich Salz <rs...@openssl.org> Reviewed-by: Richard Levitte <levi...@openssl.org> (Merged from https://github.com/openssl/openssl/pull/2894) ----------------------------------------------------------------------- Summary of changes: crypto/conf/conf_def.c | 16 +++++++-- crypto/conf/conf_err.c | 4 ++- doc/man5/config.pod | 3 +- .../conf/0d7ad6e04c0235cdc590756ceec867a05cff5823 | 41 ++++++++++++++++++++++ include/openssl/conf.h | 1 + 5 files changed, 61 insertions(+), 4 deletions(-) create mode 100644 fuzz/corpora/conf/0d7ad6e04c0235cdc590756ceec867a05cff5823 diff --git a/crypto/conf/conf_def.c b/crypto/conf/conf_def.c index 8861b3a..a7b11d1 100644 --- a/crypto/conf/conf_def.c +++ b/crypto/conf/conf_def.c @@ -20,6 +20,12 @@ #include <openssl/buffer.h> #include <openssl/err.h> +/* + * The maximum length we can grow a value to after variable expansion. 64k + * should be more than enough for all reasonable uses. + */ +#define MAX_CONF_VALUE_LENGTH 65536 + static char *eat_ws(CONF *conf, char *p); static char *eat_alpha_numeric(CONF *conf, char *p); static void clear_comments(CONF *conf, char *p); @@ -457,6 +463,8 @@ static int str_copy(CONF *conf, char *section, char **pto, char *from) } else if (IS_EOF(conf, *from)) break; else if (*from == '$') { + size_t newsize; + /* try to expand it */ rrp = NULL; s = &(from[1]); @@ -511,8 +519,12 @@ static int str_copy(CONF *conf, char *section, char **pto, char *from) CONFerr(CONF_F_STR_COPY, CONF_R_VARIABLE_HAS_NO_VALUE); goto err; } - if (!BUF_MEM_grow_clean(buf, - (strlen(p) + buf->length - (e - from)))) { + newsize = strlen(p) + buf->length - (e - from); + if (newsize > MAX_CONF_VALUE_LENGTH) { + CONFerr(CONF_F_STR_COPY, CONF_R_VARIABLE_EXPANSION_TOO_LONG); + goto err; + } + if (!BUF_MEM_grow_clean(buf, newsize)) { CONFerr(CONF_F_STR_COPY, ERR_R_MALLOC_FAILURE); goto err; } diff --git a/crypto/conf/conf_err.c b/crypto/conf/conf_err.c index b583c05..0863bc4 100644 --- a/crypto/conf/conf_err.c +++ b/crypto/conf/conf_err.c @@ -1,6 +1,6 @@ /* * Generated by util/mkerr.pl DO NOT EDIT - * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -60,6 +60,8 @@ static ERR_STRING_DATA CONF_str_reasons[] = { {ERR_REASON(CONF_R_UNABLE_TO_CREATE_NEW_SECTION), "unable to create new section"}, {ERR_REASON(CONF_R_UNKNOWN_MODULE_NAME), "unknown module name"}, + {ERR_REASON(CONF_R_VARIABLE_EXPANSION_TOO_LONG), + "variable expansion too long"}, {ERR_REASON(CONF_R_VARIABLE_HAS_NO_VALUE), "variable has no value"}, {0, NULL} }; diff --git a/doc/man5/config.pod b/doc/man5/config.pod index 24ebafb..ba9a8ab 100644 --- a/doc/man5/config.pod +++ b/doc/man5/config.pod @@ -44,7 +44,8 @@ or B<${section::name}>. By using the form B<$ENV::name> environment variables can be substituted. It is also possible to assign values to environment variables by using the name B<ENV::name>, this will work if the program looks up environment variables using the B<CONF> library -instead of calling getenv() directly. +instead of calling getenv() directly. The value string must not exceed 64k in +length after variable expansion. Otherwise an error will occur. It is possible to escape certain characters by using any kind of quote or the B<\> character. By making the last character of a line a B<\> diff --git a/fuzz/corpora/conf/0d7ad6e04c0235cdc590756ceec867a05cff5823 b/fuzz/corpora/conf/0d7ad6e04c0235cdc590756ceec867a05cff5823 new file mode 100644 index 0000000..b0ed191 --- /dev/null +++ b/fuzz/corpora/conf/0d7ad6e04c0235cdc590756ceec867a05cff5823 @@ -0,0 +1,41 @@ +=;2I8 +=$$$$$$ +=$$$$$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ += +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$$$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$$$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$ +=$$$ +=$$$$$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$ +=$$$$$ \ No newline at end of file diff --git a/include/openssl/conf.h b/include/openssl/conf.h index 462e3c9..980a51b 100644 --- a/include/openssl/conf.h +++ b/include/openssl/conf.h @@ -208,6 +208,7 @@ int ERR_load_CONF_strings(void); # define CONF_R_NO_VALUE 108 # define CONF_R_UNABLE_TO_CREATE_NEW_SECTION 103 # define CONF_R_UNKNOWN_MODULE_NAME 113 +# define CONF_R_VARIABLE_EXPANSION_TOO_LONG 116 # define CONF_R_VARIABLE_HAS_NO_VALUE 104 # ifdef __cplusplus _____ openssl-commits mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-commits