From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-m15593.qiye.163.com (mail-m15593.qiye.163.com [101.71.155.93]) (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 B21A22E8DFE; Mon, 13 Oct 2025 08:18:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=101.71.155.93 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760343533; cv=none; b=fJ6XmdNisgKsfBshY26r5VUg8qnSX0/uPiZvRWULPzvrnHk4XZgT2VBN+l2UkZOvkvBpinyR33nBqSE2y3kjO5YuZBvcQbnySrYASth1OZUbRO4cUsnNjsPZQYRdluVOy+EElapfVy7r3pLQxp15RThmhFOg+1c8hrGIBEvWCpU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760343533; c=relaxed/simple; bh=qphfDqWdBhdaHU7xGqiaEpSTwPrgSCHIq1QcZtQ6iaE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Rq1dyqihFa+FWq5/L3MlSbQB1yYsWJKv4aw5YbWr9myHMIevuwEY8XKzLOtkdKxo9mCWms5d1fLF0R1uSslaCsY87IlKy671YvJ28oK+6U4jhRu0jSlzI7Sn37XPMiaEli/HscGgubPgOSz4SOllx+zc+rFl0OJXLbMtomr+tNc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=easystack.cn; spf=pass smtp.mailfrom=easystack.cn; arc=none smtp.client-ip=101.71.155.93 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=easystack.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=easystack.cn Received: from [192.168.0.18] (unknown [218.94.118.90]) by smtp.qiye.163.com (Hmail) with ESMTP id 116f3f6a0; Mon, 13 Oct 2025 11:42:39 +0800 (GMT+08:00) Message-ID: <49645a87-b785-4538-8615-ff5b4a36d605@easystack.cn> Date: Mon, 13 Oct 2025 11:42:39 +0800 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] pidfs: fix ERR_PTR dereference in pidfd_info() To: Mateusz Guzik Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, stable@vger.kernel.org References: <20251011072927.342302-1-zhen.ni@easystack.cn> <5asnajyk3d4c66fnpmodybc7rrprhvw4jy2chrihnlcgylu5uf@hfcw24zm2w7k> From: "zhen.ni" In-Reply-To: <5asnajyk3d4c66fnpmodybc7rrprhvw4jy2chrihnlcgylu5uf@hfcw24zm2w7k> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-HM-Tid: 0a99dba9c2ec0229kunme7785e8125c24d X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWS1ZQUlXWQ8JGhUIEh9ZQVlCTklLVklMTEgaGElCHkpJSlYVFAkWGhdVGRETFh oSFyQUDg9ZV1kYEgtZQVlJSkNVQk9VSkpDVUJLWVdZFhoPEhUdFFlBWU9LSFVCQklOS1VKS0tVSk JLQlkG 在 2025/10/11 17:24, Mateusz Guzik 写道: > > Is that something you ran into or perhaps you are going off of reading > the code? > > The only way that I see to get here requires a file with > pidfs_file_operations, so AFAICS this shouuld never trigger. > > In the worst case perhaps this can WARN_ON? > > Thanks for the review. I did not hit this in real testing, but only inferred the potential issue from reading the code context. After taking another look at the call paths into pidfd_info(), I agree this is indeed an over-defensive check and not actually reachable. I'll drop this patch. Thanks for the clarification. Zhen