From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 5DB99256C64; Mon, 28 Apr 2025 13:49:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745848181; cv=none; b=GamFH4ilfm9hxA03DEtp3eaU9VW+fv9wiwInH9RZKPfRbSCArX1QqiXijHIi86ajFdVR7jJgAfL2y3NBFgnWOHUEWkSktQCvZP+Ja3TIR52BBu/uRKDo/qn9lniCatmjoLyMK3jgZ8xcdHXcmy/4B5+cDniKguAnZV2xHl7Q0Dw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745848181; c=relaxed/simple; bh=LT76VkU+lFukegnTMvC4JliKRH/Fi6SPsJ5TQpTHPC8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HhUv/8iBeu8YNMHXWZAVKpB/Pzm2NOpWfwDPE9spG5tQTaitJcXdH/0ziOD73xbkh/Js3+OC/ChoT+hWKdhycWYP/yYr4Sp+XrKIdwlkdgvAziv89pluqPC6nUhjOXnuLeNMjMlBCaRRhayDo2KdItIhiZUV6AePIHC9ysGWTDk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=j1EZ11zB; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="j1EZ11zB" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=pbGuZAKrq2M6ndsNnuI2WPrOZ34Dz7W83BsoQOyP4bg=; b=j1EZ11zBtFaXtgygx9ge6OVZf4 /ssHMzy/EOVOR3vkPZVJoI6Dt2gVmLBxhYDFgNsAhLcFYgcc4qsqOmow06Eg+PDKfy+dtl74Tws6i 6L8n0VUH9C6Pxduso1FrhESg49Gq9BCk0kJtRdeJYOa6SHOmzIPzVtXfG9V64qZcEzh+Vw/HzZ2nQ T//sUcCOyhUEcenm9LU43zNMDKcx4RX3GoMSMcmRTWKDF03uF3NpGNEMUFUMuHITW4KPnM+jC9dQo ICXLyVpR9e2e0p0CidHoPw4YYNV2oaTR1il8ULjF71kfPp/cISRTlH2a2+hyAMeRHrxrDW/xS1S0S XPFZfCUw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1u9Orb-00000006XZw-3oH7; Mon, 28 Apr 2025 13:49:39 +0000 Date: Mon, 28 Apr 2025 06:49:39 -0700 From: Christoph Hellwig To: Lizhi Xu Cc: hch@infradead.org, axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ming.lei@redhat.com, syzbot+6af973a3b8dfd2faefdc@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH V2] loop: Add sanity check for read/write_iter Message-ID: References: <20250428134812.3225991-1-lizhi.xu@windriver.com> 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-Disposition: inline In-Reply-To: <20250428134812.3225991-1-lizhi.xu@windriver.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Apr 28, 2025 at 09:48:12PM +0800, Lizhi Xu wrote: > On Mon, 28 Apr 2025 05:46:25 -0700, Christoph Hellwig wrote: > > > > and maybe add a blurb that vfs_iter_read/write had this check. > > > It makes no sence. The current issue context does not involve vfs layer > > > iter_read/write related routines. > > > > Yes. But explaining how a change caused a regression is good > > information for a commit log. > What changes? > The check in vfs_iter_read/write is not relevant to this case. > It is best to not write something irrelevant. It is releavant in that vfs_iter_read/write have the check, and removal of their used caused szybot to be able to hit this issue.