Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753252AbcDGAUw (ORCPT ); Wed, 6 Apr 2016 20:20:52 -0400 Received: from mail-pa0-f48.google.com ([209.85.220.48]:36260 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751964AbcDGAUs (ORCPT ); Wed, 6 Apr 2016 20:20:48 -0400 From: Kees Cook To: James Morris Cc: Kees Cook , Andrew Morton , Joe Perches , Mimi Zohar , Andy Shevchenko , "Serge E. Hallyn" , Kalle Valo , Mauro Carvalho Chehab , Guenter Roeck , Jiri Slaby , Paul Moore , Stephen Smalley , Casey Schaufler , Andreas Gruenbacher , Rasmus Villemoes , Ulf Hansson , Vitaly Kuznetsov , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/6] string_helpers: add kstrdup_quotable Date: Wed, 6 Apr 2016 17:20:32 -0700 Message-Id: <1459988437-3429-2-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.6.3 In-Reply-To: <1459988437-3429-1-git-send-email-keescook@chromium.org> References: <1459988437-3429-1-git-send-email-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1839 Lines: 68 Handle allocating and escaping a string safe for logging. Signed-off-by: Kees Cook --- v3: - add gfp_t, joe - reduce BUG_ON to WARN_ON, joe --- include/linux/string_helpers.h | 2 ++ lib/string_helpers.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index dabe643eb5fa..e4c597969460 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -68,4 +68,6 @@ static inline int string_escape_str_any_np(const char *src, char *dst, return string_escape_str(src, dst, sz, ESCAPE_ANY_NP, only); } +char *kstrdup_quotable(char *src, gfp_t gfp); + #endif diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 5c88204b6f1f..a8e2716e63c6 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -534,3 +535,30 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, return p - dst; } EXPORT_SYMBOL(string_escape_mem); + +/* + * Return an allocated string that has been escaped of special characters + * and double quotes, making it safe to log in quotes. + */ +char *kstrdup_quotable(char *src, gfp_t gfp) +{ + size_t slen, dlen; + char *dst; + const int flags = ESCAPE_HEX; + const char esc[] = "\f\n\r\t\v\a\e\\\""; + + if (!src) + return NULL; + slen = strlen(src); + + dlen = string_escape_mem(src, slen, NULL, 0, flags, esc); + dst = kmalloc(dlen + 1, gfp); + if (!dst) + return NULL; + + WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen); + dst[dlen] = '\0'; + + return dst; +} +EXPORT_SYMBOL_GPL(kstrdup_quotable); -- 2.6.3