From nobody Wed Dec 17 17:27:38 2025 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 8AA2B18CC1C for ; Sun, 16 Mar 2025 16:57:02 +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=1742144222; cv=none; b=pptTp2YvupG3QFushx1zkTJfjtYxqee4i2LbQv2n/t/OuQlv5HX5V/qQOUFZ0LsIWnxdLz1C6sL8whYT3M2fmlWyd50bMpM6zJtNgVi3bonxaSqsf/eQsO5ggnyWADe0W4InglmJI/VYYwnpSUjJ1koCX12KuRyBpdA0ndkkBQI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742144222; c=relaxed/simple; bh=ZnKT267z5ee5WmZRFx02q0tqr80EHFFnzkQLVXaTqGQ=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=QgQHANxYJgeyHhZT4JhgASTFCGZjAcUIsMdWNSbrxyRPLzNr5qk4UKUGJ41PWxU9ezQ5CpzwncNnsrNPC+Ax3SzWgXUG+VXv5IqOaUjuNfEhP+2LyN018qRkIGajn1dPC+fut/8ODmq6SgXmNzRx2VI/k0SOacshCMpouanDCnY= 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 BA627C4CEDD; Sun, 16 Mar 2025 16:57:00 +0000 (UTC) Date: Sun, 16 Mar 2025 12:56:57 -0400 From: Steven Rostedt To: LKML Cc: Masami Hiramatsu , Mathieu Desnoyers , Tengda Wu Subject: [for-linus][PATCH] tracing: Correct the refcount if the hist/hist_debug file fails to open Message-ID: <20250316125657.09ac3ec8@batman.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git trace/fixes Head SHA1: 0b4ffbe4888a2c71185eaf5c1a02dd3586a9bc04 Tengda Wu (1): tracing: Correct the refcount if the hist/hist_debug file fails to op= en ---- kernel/trace/trace_events_hist.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) --------------------------- commit 0b4ffbe4888a2c71185eaf5c1a02dd3586a9bc04 Author: Tengda Wu Date: Fri Mar 14 06:53:35 2025 +0000 tracing: Correct the refcount if the hist/hist_debug file fails to open =20 The function event_{hist,hist_debug}_open() maintains the refcount of 'file->tr' and 'file' through tracing_open_file_tr(). However, it does not roll back these counts on subsequent failure paths, resulting in a refcount leak. =20 A very obvious case is that if the hist/hist_debug file belongs to a specific instance, the refcount leak will prevent the deletion of that instance, as it relies on the condition 'tr->ref =3D=3D 1' within __remove_instance(). =20 Fix this by calling tracing_release_file_tr() on all failure paths in event_{hist,hist_debug}_open() to correct the refcount. =20 Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Zheng Yejian Link: https://lore.kernel.org/20250314065335.1202817-1-wutengda@huaweic= loud.com Fixes: 1cc111b9cddc ("tracing: Fix uaf issue when open the hist or hist= _debug file") Signed-off-by: Tengda Wu Signed-off-by: Steven Rostedt (Google) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_h= ist.c index ad7419e24055..53dc6719181e 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5689,12 +5689,16 @@ static int event_hist_open(struct inode *inode, str= uct file *file) guard(mutex)(&event_mutex); =20 event_file =3D event_file_data(file); - if (!event_file) - return -ENODEV; + if (!event_file) { + ret =3D -ENODEV; + goto err; + } =20 hist_file =3D kzalloc(sizeof(*hist_file), GFP_KERNEL); - if (!hist_file) - return -ENOMEM; + if (!hist_file) { + ret =3D -ENOMEM; + goto err; + } =20 hist_file->file =3D file; hist_file->last_act =3D get_hist_hit_count(event_file); @@ -5702,9 +5706,14 @@ static int event_hist_open(struct inode *inode, stru= ct file *file) /* Clear private_data to avoid warning in single_open() */ file->private_data =3D NULL; ret =3D single_open(file, hist_show, hist_file); - if (ret) + if (ret) { kfree(hist_file); + goto err; + } =20 + return 0; +err: + tracing_release_file_tr(inode, file); return ret; } =20 @@ -5979,7 +5988,10 @@ static int event_hist_debug_open(struct inode *inode= , struct file *file) =20 /* Clear private_data to avoid warning in single_open() */ file->private_data =3D NULL; - return single_open(file, hist_debug_show, file); + ret =3D single_open(file, hist_debug_show, file); + if (ret) + tracing_release_file_tr(inode, file); + return ret; } =20 const struct file_operations event_hist_debug_fops =3D {