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 A3D58625; Sat, 4 Apr 2026 00:34:07 +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=1775262847; cv=none; b=EiZw3YrQYyS00NoDwACq7gg2zUia2XFpYf2HzdF3AB9dIDCPUtwu85qdMtdNHFLRStBMf4S994gPzdJ73m0zsbvwuAXWS3IInnE0qjD4s+srxnOpQMTgTyLZShI8b9JbzV4bpcqXKQJ/v2yIaX9/EXbHynQZJIDzmpuPhjdoOMg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775262847; c=relaxed/simple; bh=fVNdL/o9S9xt6Sf7j57v4F3QUns88VfVuhlnc17JuSU=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=Vjeb5QQwBwdba2nVFkD4EssYP8UNg7YROqrUgQHe2gz/KQnYL52znqYgYkvHHjA1AYFKvDTRgaTxzkJmU3wzGcoTTbsGHIBWR90+P51B//8VB7matNveR2lOXmfBRTcdYq1ulc7JAYjBK++hjK3rCJBe8m0GRLon22bNkRZXBiA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a+77hpP5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a+77hpP5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06F2AC19421; Sat, 4 Apr 2026 00:34:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775262847; bh=fVNdL/o9S9xt6Sf7j57v4F3QUns88VfVuhlnc17JuSU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=a+77hpP5fHMsbsuQ5ERuZACAG3i3TLjmWAvSbRnfJ8ZJouEv4FZtTQRGF079UhkAe sY+X+jvJsGGj3LS0MuFTfE13CXPAJpa/WOUE6ZAC3Ed96bAi8I/gWxw4lOSufCsBzp lQTD0R5p8IEYNk4lxizWZclzgfxLyFAR88UMpTMqWjW9gxVjAliOd4QhxkvxjDC46h 1TXuJHsbPXz2cCkLsc7BMWI2JsuztWFzDutt8KmMvx6xdU2qZYPyl95ZKqZDBY0b7X 174dYT6udFyNmfmUgiBz9CKVuGBidur51w7rHY9rLI3VxqXBr8Q2Ehuf46rxAM0FlM k7mSlQHSuJEag== Date: Sat, 4 Apr 2026 09:33:59 +0900 From: Masami Hiramatsu (Google) To: Pengpeng Hou Cc: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] tracing/probe: reject empty immediate strings Message-Id: <20260404093359.e3bc3f7ededeba6a73858e5d@kernel.org> In-Reply-To: <20260401160315.88518-1-pengpeng@iscas.ac.cn> References: <20260330062920.40766-1-pengpeng@iscas.ac.cn> <20260401160315.88518-1-pengpeng@iscas.ac.cn> X-Mailer: Sylpheed 3.8.0beta1 (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-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 2 Apr 2026 00:03:15 +0800 Pengpeng Hou wrote: > parse_probe_arg() accepts quoted immediate strings and passes the body > after the opening quote to __parse_imm_string(). That helper currently > computes strlen(str) and immediately dereferences str[len - 1], which > underflows when the body is empty. > > Reject empty immediate strings before checking for the closing quote. > Oops, good catch! Let me pick it. Thank you! > Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support") > Signed-off-by: Pengpeng Hou > --- > Changes since v1: > - resend as a standalone patch instead of part of an accidental > cross-subsystem 1/4 series > > kernel/trace/trace_probe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index e0a5dc86c07e..e1c73065dae5 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -1068,7 +1068,7 @@ static int __parse_imm_string(char *str, char **pbuf, int offs) > { > size_t len = strlen(str); > > - if (str[len - 1] != '"') { > + if (!len || str[len - 1] != '"') { > trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); > return -EINVAL; > } > -- > 2.50.1 (Apple Git-155) > -- Masami Hiramatsu (Google)