From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) (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 44E701C8632 for ; Wed, 11 Jun 2025 15:49:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749656965; cv=none; b=fF3cl7jjRRV7YbKzowkapMKv7OTX4mmW1fILsPqnpwGSEqindIhNzKhCCb8OZiie48O0DFP8TCQtKc/CrFURin/iDkf/0Mk0PCi6E5wGjhbav0T3GRCB690zXtWONeEReHeZ8Z/D8eWk6nLCoKycFXhU9VDnyXJQT2aV57wtAQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749656965; c=relaxed/simple; bh=Vsu5Xaf2CfmWYXrEWUU8kTg6xy3/CnahfubB8AomyEw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=QhrBAjs2T93AmsjmBECXWdK/UXDfK3TK+z5EpKjt3oxbk/Zi3/XnAcwSPmRQQ5NVDv1aI3sWR1tLGLyZRfTUAnHzLhW9WjrvXx6KD6G2cGLM1IqawqxDtH+TJYe6WbUmyR92v5pKe1DJKYub4fwViKrKR/VPKuaYiaat2eObowE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=BLMetV01; arc=none smtp.client-ip=91.218.175.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="BLMetV01" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1749656960; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=NkpbyMsiJRwWnx6iOR+RLlbhyzNlbJ3e38I3A+4NmfI=; b=BLMetV01lS4FXWjpoxALr+a7Mi0irlvKqYcAZBywjBIwgNGKzGMwf6SP0SwobrqhyTbR8H NQ/nTgeRdr9+LbZ4t/A+vxRUTO28kF4R6uvFYTrAwmTj5i/qgFhOAX9bHiICSohUcwmfK3 WvRPHYKGvp0Puq6S/5gBm2Q5AFHG7m4= From: Tao Chen To: kpsingh@kernel.org, mattbobrowski@google.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Tao Chen Subject: [PATCH bpf-next] bpf: clear user buf when bpf_d_path failed Date: Wed, 11 Jun 2025 23:48:58 +0800 Message-ID: <20250611154859.259682-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT The bpf_d_path() function may fail. If it does, clear the user buf, like bpf_probe_read etc. Signed-off-by: Tao Chen --- kernel/trace/bpf_trace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 0998cbbb963..bb1003cb271 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -916,11 +916,14 @@ BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) * potentially broken verifier. */ len = copy_from_kernel_nofault(©, path, sizeof(*path)); - if (len < 0) + if (len < 0) { + memset(buf, 0, sz); return len; + } p = d_path(©, buf, sz); if (IS_ERR(p)) { + memset(buf, 0, sz); len = PTR_ERR(p); } else { len = buf + sz - p; -- 2.48.1