From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) (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 E005931E82E; Fri, 15 May 2026 23:16:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778887001; cv=none; b=rUB7GKQPDib94vQy9kDTulgKCAWNdfBHmZr2FjXRg71pUWmXI9R8ClbjD5whT4HLWTEVROmO9rV4LQ9qDpkIaJg3bofiS1H2ygUa2h+gF0VkBPYx509mi2jKHCdJ+pAkxM8TrzaA8YM9hq7V5TeHDewp6cUboiCkBI9NDTUWPfU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778887001; c=relaxed/simple; bh=+irwJ3Om1qyAb+qmmQ5h/jnyTUHKJo9wu4T6k6KN060=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=WztSNFTiY2EaOqwrwEsIaDJ/e3WkX9rw1mb8KJHM5So6wyB7zm9OoobJZT2XZhRqlvVM3zv6haLEC/Q8fG7Vr8aHGaho6cIf5K8JqGT+3MFw64DkaeTMWHgz27rpXvAgiDqtTsds31PiwKT94ICMtkQt0729edPSQoyz/oXDJgo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf03.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id CDB7C140275; Fri, 15 May 2026 23:16:35 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf03.hostedemail.com (Postfix) with ESMTPA id 0D0C46000E; Fri, 15 May 2026 23:16:31 +0000 (UTC) Date: Fri, 15 May 2026 19:16:30 -0400 From: Steven Rostedt To: Anubhav Shelat Cc: mpetlan@redhat.com, Masami Hiramatsu , Mathieu Desnoyers , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Thomas Falcon , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH v4 3/3] tracefs: make root directory world-traversable Message-ID: <20260515191630.2276b241@fedora> In-Reply-To: <20260515194010.93725-5-ashelat@redhat.com> References: <20260515194010.93725-2-ashelat@redhat.com> <20260515194010.93725-5-ashelat@redhat.com> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 6fwwxo3fr6raqbmugu3agsj555bc9jkk X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: 0D0C46000E X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/F4EzRsn/B3uDMumpeD+MZTewUy5t4Rlk= X-HE-Tag: 1778886991-828779 X-HE-Meta: U2FsdGVkX1/oL62XGgudii9qqRDXSw8IoJpH5ncJxAqIDuGscZG6EYrT4JslXZJaLPcVjNkcN9ztKiFqMP4d3sucjQDY7vfpOcHPGxnOC7xAT3YlmM93mqpqpz/dqpjTF+5t7Uk3/84UO4BFrtJtQzWx54/QD8gk2We51MMUSoT+BO87ghpKFp12XdCslXKSgsISX0QvCXrY0yyAbZxG3k+XH2GGhtBi1FUGCPvax6WaslDEnXE/QEHNFiQlY9kkYP4kTmwxIE/guBYesbxuTvLSCQf3limSU2usgtULFzNjl8aTPGqbMBdAGEokrdGI1woY6NjrZHk8PK3MYRfmaQzhW3cUa7kjlRxO9Gyu8GYt66WVy09E5A== On Fri, 15 May 2026 15:40:07 -0400 Anubhav Shelat wrote: > Change the default tracefs mount mode from 0700 to 0755. This allows > unprivileged users to access the eventfs directories underneath which > already use 0755. > > Tracing data files use mode 0440 and 0640 so they are not exposed by > this change. Only the format and id files, which have been marked as > work-readable, become accessible. > > Directory listings of kprobes and uprobes, which contain functions or > binaries, become visible to unprivileged users but do not contain kernel > addresses. Admins using probes can restore the previous behavior with > chmod or mount -o mode=700. > I've been thinking about this and I believe a better approach is to make a eventfs that is mounted at: /sys/kernel/events and be the same directory structure as /sys/kernel/tracing/events but only contain read only files like "id" and "format". This directory would be mounted as 555 and readable by all. -- Steve