From patchwork Fri Dec 20 15:33:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13916893 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6181B2156EC; Fri, 20 Dec 2024 15:32:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734708752; cv=none; b=TEzwzbEweI3TMPmbIW6XZMTHgMw7ARlsLkEzfkNrt5UmNjRCIg1wsept1DAxnIJ1+ziAcOjvJT2Pz2nkK1rH4RcOGeeF87oto2UVMyGatuuVCQeW9B6I3FygcBZoQPkl4kxCwXqvWI67ADX/yrbEgf6IKJ4nbR4r0VSmIjlHZjI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734708752; c=relaxed/simple; bh=8wywkdRWworUBNcYyAaj0Iz13WAXwwVWHDmsKj9i3zw=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=iXMbHbmeiROC8+5FcFDIqtcvqMD+LnYkWibLKyDAD2z0PRDTG2J2k2QCNLZRq6NNRkTWEUqsLLiRvcf+dZq3aqB5ioeyKCgIPw/njp2/ZKH7JBg4pKZgjQ8U4IkVrLVqANySDQZP3KIpmGoGio1mBvPcOGI5F70N6+WmFXe5D2k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD535C4CED3; Fri, 20 Dec 2024 15:32:30 +0000 (UTC) Date: Fri, 20 Dec 2024 10:33:13 -0500 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mathieu Desnoyers , Peter Zijlstra , Kees Cook , Andy Shevchenko , linux-hardening@vger.kernel.org Subject: [PATCH v2] tracing/string: Create and use __free(argv_free) in trace_dynevent.c Message-ID: <20241220103313.4a74ec8e@gandalf.local.home> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Steven Rostedt The function dyn_event_release() uses argv_split() which must be freed via argv_free(). It contains several error paths that do a goto out to call argv_free() for cleanup. This makes the code complex and error prone. Create a new __free() directive __free(argv_free) that will call argv_free() for data allocated with argv_split(), and use it in the dyn_event_release() function. Cc: Kees Cook Cc: Andy Shevchenko Cc: linux-hardening@vger.kernel.org Signed-off-by: Steven Rostedt (Google) --- Changes since v1: https://lore.kernel.org/all/20241219201346.029319524@goodmis.org/ - Moved include of cleanup.h up to be more alphabetically ordered include/linux/string.h | 3 +++ kernel/trace/trace_dynevent.c | 23 +++++++---------------- 2 files changed, 10 insertions(+), 16 deletions(-) diff --git a/include/linux/string.h b/include/linux/string.h index 493ac4862c77..86d5d352068b 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -4,6 +4,7 @@ #include #include +#include /* for DEFINE_FREE() */ #include /* for inline */ #include /* for size_t */ #include /* for NULL */ @@ -312,6 +313,8 @@ extern void *kmemdup_array(const void *src, size_t count, size_t element_size, g extern char **argv_split(gfp_t gfp, const char *str, int *argcp); extern void argv_free(char **argv); +DEFINE_FREE(argv_free, char **, if (!IS_ERR_OR_NULL(_T)) argv_free(_T)) + /* lib/cmdline.c */ extern int get_option(char **str, int *pint); extern char *get_options(const char *str, int nints, int *ints); diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 4376887e0d8a..a322e4f249a5 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -74,24 +74,19 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type struct dyn_event *pos, *n; char *system = NULL, *event, *p; int argc, ret = -ENOENT; - char **argv; + char **argv __free(argv_free) = argv_split(GFP_KERNEL, raw_command, &argc); - argv = argv_split(GFP_KERNEL, raw_command, &argc); if (!argv) return -ENOMEM; if (argv[0][0] == '-') { - if (argv[0][1] != ':') { - ret = -EINVAL; - goto out; - } + if (argv[0][1] != ':') + return -EINVAL; event = &argv[0][2]; } else { event = strchr(argv[0], ':'); - if (!event) { - ret = -EINVAL; - goto out; - } + if (!event) + return -EINVAL; event++; } @@ -101,10 +96,8 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type event = p + 1; *p = '\0'; } - if (!system && event[0] == '\0') { - ret = -EINVAL; - goto out; - } + if (!system && event[0] == '\0') + return -EINVAL; mutex_lock(&event_mutex); for_each_dyn_event_safe(pos, n) { @@ -120,8 +113,6 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type } tracing_reset_all_online_cpus(); mutex_unlock(&event_mutex); -out: - argv_free(argv); return ret; }