From patchwork Fri Mar 14 06:53:35 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tengda Wu X-Patchwork-Id: 14016346 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 F19C6C8C7; Fri, 14 Mar 2025 07:07:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741936045; cv=none; b=U4nxFmrqPx9fCM2RGWfLkrTxnEH+C3m+sYRLW2g5skzn0JjMoL2WxRq8OZ2qcQOixrmTbSdyNToglX96NbjEsEDCTmDzo4M4dG/LZ5FC6aKese0xhfS3DllQMmN5zoU0rZa+tQG87pE+nfGt2YKQBwbK2ZZapq4DL3r8t7O6Sp4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741936045; c=relaxed/simple; bh=+kOlz/Q28jG0cYfTsBiLwIHMZVZA54BpzkbvmNbTCks=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=SDUjUa96/p/yGOztZfRjNoBEXcpO8pjc0chnGdfyR405X/J4B2nhuwgC6WyuVANkScdCm0QYHrcN32NavY+K+oM0YcLres2GlZaAdEg8itc955ds/b6NAbVGKCrMyBFnHX5ey5sgl575F5j6I+6zEJRmgt3VdJg0JccW5DNEsms= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4ZDb5X1p4rz4f3jXT; Fri, 14 Mar 2025 15:06:56 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id B14CE1A084E; Fri, 14 Mar 2025 15:07:18 +0800 (CST) Received: from huawei.com (unknown [10.67.174.45]) by APP4 (Coremail) with SMTP id gCh0CgDXN1yf1dNnGzXOGQ--.57039S2; Fri, 14 Mar 2025 15:07:18 +0800 (CST) From: Tengda Wu To: Steven Rostedt , Masami Hiramatsu Cc: Mathieu Desnoyers , Zheng Yejian , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] tracing: Correct the refcount if the hist/hist_debug file fails to open Date: Fri, 14 Mar 2025 06:53:35 +0000 Message-Id: <20250314065335.1202817-1-wutengda@huaweicloud.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgDXN1yf1dNnGzXOGQ--.57039S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw1kur43AFy7XrWxAr15XFb_yoW5JF4Upr WrJrn8Kry8J3WIgr1fAan7ZFyfZ3y8tFWxWa4Du34ftrn8W34Fqay7K345ZF15trZ5Jrya qa1qgry2krWUuaDanT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUyEb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI 7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxV Cjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY 6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6x AIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY 1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU1ZmRUUUUUU== X-CM-SenderInfo: pzxwv0hjgdqx5xdzvxpfor3voofrz/ 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. 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 == 1' within __remove_instance(). Fix this by calling tracing_release_file_tr() on all failure paths in event_{hist,hist_debug}_open() to correct the refcount. Fixes: 1cc111b9cddc ("tracing: Fix uaf issue when open the hist or hist_debug file") Signed-off-by: Tengda Wu Cc: stable@vger.kernel.org # v6.7+ --- v2: Fix all error path exits after taking the refcount. kernel/trace/trace_events_hist.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.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, struct file *file) guard(mutex)(&event_mutex); event_file = event_file_data(file); - if (!event_file) - return -ENODEV; + if (!event_file) { + ret = -ENODEV; + goto err; + } hist_file = kzalloc(sizeof(*hist_file), GFP_KERNEL); - if (!hist_file) - return -ENOMEM; + if (!hist_file) { + ret = -ENOMEM; + goto err; + } hist_file->file = file; hist_file->last_act = get_hist_hit_count(event_file); @@ -5702,9 +5706,14 @@ static int event_hist_open(struct inode *inode, struct file *file) /* Clear private_data to avoid warning in single_open() */ file->private_data = NULL; ret = single_open(file, hist_show, hist_file); - if (ret) + if (ret) { kfree(hist_file); + goto err; + } + return 0; +err: + tracing_release_file_tr(inode, file); return ret; } @@ -5979,7 +5988,10 @@ static int event_hist_debug_open(struct inode *inode, struct file *file) /* Clear private_data to avoid warning in single_open() */ file->private_data = NULL; - return single_open(file, hist_debug_show, file); + ret = single_open(file, hist_debug_show, file); + if (ret) + tracing_release_file_tr(inode, file); + return ret; } const struct file_operations event_hist_debug_fops = {