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[209.132.180.131]) by mx.google.com with ESMTPS id w79si47127212pfi.99.2016.02.01.08.21.31 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Feb 2016 08:21:32 -0800 (PST) Received-SPF: pass (google.com: domain of libc-alpha-return-66844-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Authentication-Results: mx.google.com; spf=pass (google.com: domain of libc-alpha-return-66844-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) smtp.mailfrom=libc-alpha-return-66844-patch=linaro.org@sourceware.org; dkim=pass header.i=@sourceware.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:in-reply-to :references; q=dns; s=default; b=vey+bFWA72VBY80368I5lRiqt2f5FCL oLt8qdYfulMoeVSURzb8DbZE1hhfTI+/pF9c3tOaqI4C7C7Dl249fnWXm4pkHiXj VIrCXhV23ZjYr3+scUvJvXSOYnhxyQuqIfvuxX/IlIYDYnYAzn08eVyd2OhxbXRv eh49VDZHvUiI= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:in-reply-to :references; s=default; bh=qkKwOPUSc3vJnwTtK4fFIoN/P/A=; b=hlkXD 6aRAHlRdFOxFbyEDllnVyfB+gLvVS3GISwHBGXUqa9oUl4b4x8DUFXnlKYWlykms YnDZkrmazg9UVW9nLwXnJ/XHgWprK11WSL9FO7y8DC3VsP0jcoxJLn8Yia90Gxaw v2ktbubnxMp4QG/7AvCx4qrLW+ANzYDVsi0Irg= Received: (qmail 75475 invoked by alias); 1 Feb 2016 16:21:18 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 75331 invoked by uid 89); 1 Feb 2016 16:21:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=BAYES_00, KAM_ASCII_DIVIDERS, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=no version=3.3.2 spammy=exceed, 1757 X-HELO: mail-yk0-f182.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=9HqoclKhCeTK7TSdQR42JfSM6easTFPG759D5bfC5kI=; b=Cn+T98ldWv9ZzT76atYbQVwRVaCxpOeZh2D6ouVcyQmCT5JRLwsWAgAX9j2Njv/3A6 163L0fqqH21F7cArKETWwHEv6HXvX3AzLT/VpkK/1OKA1FydL68MXHFDu/ObB0q6YiKa QpC4o3K7iSjXzojtmyqDplgOegBVW8JlT+vyIZf1uQMm29sEi+Ay7HsMoU2ymBITWNtk Pu+d0skrbCpMtB6IEPxFMZhgIr2wofWaxgdX9FkkDwRhANqjvM4wGZ2wzu3jUJplqeQr n8KpOsp4VLeu4kG3H3cKTLsMidc5JNLmKExlJo/7Wwk9aol70flRwaVb1njH33slnPHC qXcg== X-Gm-Message-State: AG10YOSzYKojZbwEgNf/TkB1hgUQLaIbFJ/ZK1Za5CWfK7+QSb1JWvxrOoa01tgxZ2+ZbQsT X-Received: by 10.129.57.135 with SMTP id g129mr11495855ywa.244.1454343673800; Mon, 01 Feb 2016 08:21:13 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH v2 1/3] posix: Remove dynamic memory allocation from execl{e, p} Date: Mon, 1 Feb 2016 14:21:03 -0200 Message-Id: <1454343665-1706-2-git-send-email-adhemerval.zanella@linaro.org> In-Reply-To: <1454343665-1706-1-git-send-email-adhemerval.zanella@linaro.org> References: <1454343665-1706-1-git-send-email-adhemerval.zanella@linaro.org> GLIBC execl{e,p} implementation might use malloc if the total number of i arguments exceed initial assumption size (1024). This might lead to issue in two situations: 1. execl/execle is stated to be async-signal-safe by POSIX [1]. However if execl is used in a signal handler with a large argument set (that may call malloc internally) and the resulting call fails, it might lead malloc in the program in a bad state. 2. If the functions are used in a vfork/clone(VFORK) situation it also might issue malloc internal bad state. This patch fixes it by using stack allocation instead. It also fixes BZ#19534. Tested on x86_64. Changes from previous version: - Remove arbitrary limit on stack allocation for argument handling (it is arbitrary and does no impose any limit since it does not consider current stack size neither stack size limit). [1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html [BZ #19534] * posix/execl.c (execl): Remove dynamic memory allocation. * posix/execle.c (execle): Likewise. * posix/execlp.c (execlp): Likewise. --- posix/execl.c | 65 +++++++++++++++++---------------------------------------- posix/execle.c | 66 ++++++++++++++++++---------------------------------------- posix/execlp.c | 64 +++++++++++++++++--------------------------------------- 4 files changed, 65 insertions(+), 137 deletions(-) -- 1.9.1 diff --git a/posix/execl.c b/posix/execl.c index 102d19d..8b8a324 100644 --- a/posix/execl.c +++ b/posix/execl.c @@ -16,58 +16,31 @@ . */ #include +#include #include -#include -#include -#include - -#include - +#include /* Execute PATH with all arguments after PATH until a NULL pointer and environment from `environ'. */ int execl (const char *path, const char *arg, ...) { -#define INITIAL_ARGV_MAX 1024 - size_t argv_max = INITIAL_ARGV_MAX; - const char *initial_argv[INITIAL_ARGV_MAX]; - const char **argv = initial_argv; - va_list args; - - argv[0] = arg; - - va_start (args, arg); - unsigned int i = 0; - while (argv[i++] != NULL) - { - if (i == argv_max) - { - argv_max *= 2; - const char **nptr = realloc (argv == initial_argv ? NULL : argv, - argv_max * sizeof (const char *)); - if (nptr == NULL) - { - if (argv != initial_argv) - free (argv); - va_end (args); - return -1; - } - if (argv == initial_argv) - /* We have to copy the already filled-in data ourselves. */ - memcpy (nptr, argv, i * sizeof (const char *)); - - argv = nptr; - } - - argv[i] = va_arg (args, const char *); - } - va_end (args); - - int ret = __execve (path, (char *const *) argv, __environ); - if (argv != initial_argv) - free (argv); - - return ret; + int argc; + va_list ap; + va_start (ap, arg); + for (argc = 1; va_arg (ap, const char *); argc++) + continue; + va_end (ap); + + int i; + char *argv[argc+1]; + va_start (ap, arg); + argv[0] = (char*) arg; + for (i = 1; i < argc; i++) + argv[i] = va_arg (ap, char *); + argv[i] = NULL; + va_end (ap); + + return __execve (path, argv, __environ); } libc_hidden_def (execl) diff --git a/posix/execle.c b/posix/execle.c index 8edc03a..1a0c9ee 100644 --- a/posix/execle.c +++ b/posix/execle.c @@ -17,57 +17,31 @@ #include #include -#include -#include -#include - -#include +#include +#include /* Execute PATH with all arguments after PATH until a NULL pointer, and the argument after that for environment. */ int execle (const char *path, const char *arg, ...) { -#define INITIAL_ARGV_MAX 1024 - size_t argv_max = INITIAL_ARGV_MAX; - const char *initial_argv[INITIAL_ARGV_MAX]; - const char **argv = initial_argv; - va_list args; - argv[0] = arg; - - va_start (args, arg); - unsigned int i = 0; - while (argv[i++] != NULL) - { - if (i == argv_max) - { - argv_max *= 2; - const char **nptr = realloc (argv == initial_argv ? NULL : argv, - argv_max * sizeof (const char *)); - if (nptr == NULL) - { - if (argv != initial_argv) - free (argv); - va_end (args); - return -1; - } - if (argv == initial_argv) - /* We have to copy the already filled-in data ourselves. */ - memcpy (nptr, argv, i * sizeof (const char *)); - - argv = nptr; - } - - argv[i] = va_arg (args, const char *); - } - - const char *const *envp = va_arg (args, const char *const *); - va_end (args); - - int ret = __execve (path, (char *const *) argv, (char *const *) envp); - if (argv != initial_argv) - free (argv); - - return ret; + int argc; + va_list ap; + va_start (ap, arg); + for (argc = 1; va_arg (ap, const char *); argc++) + continue; + va_end (ap); + + int i; + char *argv[argc+1]; + char **envp; + va_start (ap, arg); + argv[0] = (char*) arg; + for (i = 1; i < argc; i++) + argv[i] = va_arg (ap, char *); + envp = va_arg (ap, char **); + va_end (ap); + + return __execve (path, argv, envp); } libc_hidden_def (execle) diff --git a/posix/execlp.c b/posix/execlp.c index 6700994..a0e1859 100644 --- a/posix/execlp.c +++ b/posix/execlp.c @@ -17,11 +17,8 @@ #include #include -#include -#include -#include - -#include +#include +#include /* Execute FILE, searching in the `PATH' environment variable if it contains no slashes, with all arguments after FILE until a @@ -29,45 +26,22 @@ int execlp (const char *file, const char *arg, ...) { -#define INITIAL_ARGV_MAX 1024 - size_t argv_max = INITIAL_ARGV_MAX; - const char *initial_argv[INITIAL_ARGV_MAX]; - const char **argv = initial_argv; - va_list args; - - argv[0] = arg; - - va_start (args, arg); - unsigned int i = 0; - while (argv[i++] != NULL) - { - if (i == argv_max) - { - argv_max *= 2; - const char **nptr = realloc (argv == initial_argv ? NULL : argv, - argv_max * sizeof (const char *)); - if (nptr == NULL) - { - if (argv != initial_argv) - free (argv); - va_end (args); - return -1; - } - if (argv == initial_argv) - /* We have to copy the already filled-in data ourselves. */ - memcpy (nptr, argv, i * sizeof (const char *)); - - argv = nptr; - } - - argv[i] = va_arg (args, const char *); - } - va_end (args); - - int ret = execvp (file, (char *const *) argv); - if (argv != initial_argv) - free (argv); - - return ret; + int argc; + va_list ap; + va_start (ap, arg); + for (argc = 1; va_arg (ap, const char *); argc++) + continue; + va_end (ap); + + int i; + char *argv[argc+1]; + va_start (ap, arg); + argv[0] = (char*) arg; + for (i = 1; i < argc; i++) + argv[i] = va_arg (ap, char *); + argv[i] = NULL; + va_end (ap); + + return __execvpe (file, argv, __environ); } libc_hidden_def (execlp)