From mboxrd@z Thu Jan 1 00:00:00 1970 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 C50952AB21 for ; Wed, 20 Sep 2023 11:58:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 462E5C433C8; Wed, 20 Sep 2023 11:58:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695211136; bh=SrIwWrBd4lHZKs2cfeFkK1Xi07Byemn82W+8FE/ztY0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MOHiJaz55dTjUDAiOV/r3HlXARcUrSppIC9qVbz0cpaj5byaGpPjXcsCeOAbSPwM4 etDZwF28sv3mlAW/TxsKNOSPKJAkwMCHHrbQLptHR1Si5zIvvrZmknHduUfQcvmOgw 4rkjoVbITXYhyb6y3Jb2lAbO0Dl2ah3tZkdAEDnI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masami Hiramatsu , Mark Rutland , Andrew Morton , Zheng Yejian , Linux Kernel Functional Testing , Naresh Kamboju , "Steven Rostedt (Google)" Subject: [PATCH 6.1 122/139] tracing: Have tracing_max_latency inc the trace array ref count Date: Wed, 20 Sep 2023 13:30:56 +0200 Message-ID: <20230920112840.131458424@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112835.549467415@linuxfoundation.org> References: <20230920112835.549467415@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (Google) commit 7d660c9b2bc95107f90a9f4c4759be85309a6550 upstream. The tracing_max_latency file points to the trace_array max_latency field. For an instance, if the file is opened and the instance is deleted, reading or writing to the file will cause a use after free. Up the ref count of the trace_array when tracing_max_latency is opened. Link: https://lkml.kernel.org/r/20230907024803.666889383@goodmis.org Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Andrew Morton Cc: Zheng Yejian Fixes: 8530dec63e7b4 ("tracing: Add tracing_check_open_get_tr()") Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1729,7 +1729,7 @@ static void trace_create_maxlat_file(str init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq); tr->d_max_latency = trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, - d_tracer, &tr->max_latency, + d_tracer, tr, &tracing_max_lat_fops); } @@ -1762,7 +1762,7 @@ void latency_fsnotify(struct trace_array #define trace_create_maxlat_file(tr, d_tracer) \ trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \ - d_tracer, &tr->max_latency, &tracing_max_lat_fops) + d_tracer, tr, &tracing_max_lat_fops) #endif @@ -6604,14 +6604,18 @@ static ssize_t tracing_max_lat_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos); + struct trace_array *tr = filp->private_data; + + return tracing_nsecs_read(&tr->max_latency, ubuf, cnt, ppos); } static ssize_t tracing_max_lat_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos); + struct trace_array *tr = filp->private_data; + + return tracing_nsecs_write(&tr->max_latency, ubuf, cnt, ppos); } #endif @@ -7668,10 +7672,11 @@ static const struct file_operations trac #ifdef CONFIG_TRACER_MAX_TRACE static const struct file_operations tracing_max_lat_fops = { - .open = tracing_open_generic, + .open = tracing_open_generic_tr, .read = tracing_max_lat_read, .write = tracing_max_lat_write, .llseek = generic_file_llseek, + .release = tracing_release_generic_tr, }; #endif