From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09EA7CE837D for ; Mon, 30 Sep 2024 18:15:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 945D928001A; Mon, 30 Sep 2024 14:15:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 91C54280017; Mon, 30 Sep 2024 14:15:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E40728001A; Mon, 30 Sep 2024 14:15:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 5DA44280017 for ; Mon, 30 Sep 2024 14:15:08 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id E699680AAA for ; Mon, 30 Sep 2024 18:15:07 +0000 (UTC) X-FDA: 82622206254.02.EEB72B8 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf07.hostedemail.com (Postfix) with ESMTP id F1B7E40017 for ; Mon, 30 Sep 2024 18:15:02 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="tY8sFwM/"; spf=none (imf07.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1727719938; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=wOCs00RL/8YdRkEJRfFh/lmIJtXzREnR4LZwIYVds8U=; b=qL/by/RmNAnuBjYP5VvfcYRSuGAxlhK5c1isD3zanbGDz9oAsFdD21uJpI5iv8IsrOwisr K7+XB2yfmKR96GblPpJJE8Zoy2+82X3wc8VQoe46jGIeFB7UZKgjxJ1tIdH8l5LAPZf94E XceSarxkvdlyBl8QGSlDzsbW6Oi9xuE= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="tY8sFwM/"; spf=none (imf07.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1727719938; a=rsa-sha256; cv=none; b=Cm7rjQqJ+A0TJk8EGTwPi7twbj2bJ4G7UMaJJsdD75Lsd/hPUYA53L2JubnIiAJBSVwhna kTJxHU+BjGc2uxBu06+q8NEpDU+03Ae3UUVqDAxhqqoNuLc1cerX/AzL8lVfd6F4C4tKEw MnLCwSGHDpuEEcvT5NlsFDpZa3+nxQg= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=wOCs00RL/8YdRkEJRfFh/lmIJtXzREnR4LZwIYVds8U=; b=tY8sFwM/UPJOVlNnRtqgeVINuu YTywwj0+LVVutFg+BCjyc3UXVwt+4Ewdu5LPer24IMeYcTpg4+6X3fHff7G05aUx7cVLcRtd2olyT ZoRcwDi0Pfv88DRDOudHTVSTpbQmghhxZgu084Je2YkAwvBHKw0032R2END4SPDvUI0hHsH1V/x8w 2qFrdqnoBbPwpV0w3pIqPTCn0iZ8MkMA8t/BclrxjsyqkL5IGKLecEY3BhwzJu+m/2KChnId+Eate 5j4XM1B1h+gx8csuzA/Q4eGpHpOF3mb4XRo9PIXbsvdqvA7H6gqRN7oofpHEMchanvd64DLQ3DnTV JCiX2sQg==; Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1svKvC-00000000Jgz-3OLb; Mon, 30 Sep 2024 18:14:58 +0000 Date: Mon, 30 Sep 2024 19:14:58 +0100 From: Matthew Wilcox To: Gianfranco Trad Cc: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, skhan@linuxfoundation.org, syzbot+4089e577072948ac5531@syzkaller.appspotmail.com Subject: Re: [PATCH v2] Fix NULL pointer dereference in read_cache_folio Message-ID: References: <20240929230548.370027-3-gianf.trad@gmail.com> <20240930090225.28517-2-gianf.trad@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240930090225.28517-2-gianf.trad@gmail.com> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: F1B7E40017 X-Stat-Signature: qrqrnf1q9se8whi37w3nei66kx8y6ooz X-Rspam-User: X-HE-Tag: 1727720102-960727 X-HE-Meta: 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 7plQz9Qz QPuQ2RlyaKNek13weuOuRBjZmrP66mHmvKJMKM3/UuDfpSsgCy2afsVx/fHKSgnO/mFRB5DpKmAqvwQ+Ub4ZoP3rFLtA6m3DEQRW5meCSyPnBFd7pi93PYKo3lK3X9kUpb96U228apspWtw++gAD69RCMzmrnQdXHcgpwuGsZN0bQCDTfp9dmMH7DHoPG5ORPnoo3fQhz2FTzudKb1DMhsNxyVSxRiAffiUxJfHvkBO8cvj6sSV47VZi1+yOVeu5/z/Mej1Z1PmPvJQIu/o5lN92xc94M42tLtgeSHxvjvMx2GPNnTzLCPrSr4x8xiHosP6nwJRENl9GX1lHOnFef7V4vDUogFBQa9KPzEi3vlDv3EOs3h+LrVdeqiw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Sep 30, 2024 at 11:02:26AM +0200, Gianfranco Trad wrote: > @@ -2360,6 +2360,8 @@ static int filemap_read_folio(struct file *file, filler_t filler, > /* Start the actual read. The read will unlock the page. */ > if (unlikely(workingset)) > psi_memstall_enter(&pflags); > + if (!filler) > + return -EIO; This is definitely wrong because you enter memstall, but do not exit it. As Andrew says, the underlying problem is that the filesystem does not implement ->read_folio. Which filesystem is this? > error = filler(file, folio); > if (unlikely(workingset)) > psi_memstall_leave(&pflags); > -- > 2.43.0 >