From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 736BB52F7A for ; Wed, 22 May 2024 10:56:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716375421; cv=none; b=F5TOo0H6OZASKLlIvyLQ4bArJT6KaCY+EOcuOTnryNZbDgp5JV+YzySrkHHHCqpHHffztlQ9dJQo33OchSl6Br4XhsLU/IF2DXZB52gcSxt/BLUhMoJxpoICXLlumM7NT56qjfjVpnYGyp8e1WE/EroNgc4UhTudZzxcSZjQXSs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716375421; c=relaxed/simple; bh=6Hksgokkl0HBv+oqPZJxKHQYHHUqeBHix5eB5WAxXYQ=; h=From:In-Reply-To:References:To:Cc:Subject:MIME-Version: Content-Type:Date:Message-ID; b=flPPN6bRfH6WQZy4twye9ubAGLbmEOkRCSi+VeRpYEKRp2fah4LFA61641FYe8T7zMfhWpJajas70cHV5ZzDH8cX9KOoy3IZQeKh8EiHzWCiZArWh/CA5K7V4J3SUwakKTu9AXj8FQEnHbNszOkBjJHDJNMtAmprfrzcGgv0Kqc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=famSj20R; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="famSj20R" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1716375418; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=UeDpmePfXLmxKAjowHlsgo0j+sPs3iu7AV0EsR6geB4=; b=famSj20RZ3EYikSflOYAxwCYgWIQ2DKnhkH85TTUgANUATij/yDmNZhtJJR39BlP/JsrhN Iscio5DNXq4ot92TazhxRMlq2w34uItnv/IzkIJIt5pAyLnvNlij39gsv3vjfItAPj7gO+ upwdrSEL0J99BC4o/KbJMj2fdvo6DLg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-554-2dZ_UjK8Ol2vygMKCUcLKQ-1; Wed, 22 May 2024 06:56:56 -0400 X-MC-Unique: 2dZ_UjK8Ol2vygMKCUcLKQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5A2D585A58C; Wed, 22 May 2024 10:56:56 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.20]) by smtp.corp.redhat.com (Postfix) with ESMTP id 19553200B4D2; Wed, 22 May 2024 10:56:53 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <0000000000005be0aa061846f8d6@google.com> To: asmadeus@codewreck.org Cc: dhowells@redhat.com, syzbot , ericvh@kernel.org, linux-kernel@vger.kernel.org, linux_oss@crudebyte.com, lucho@ionkov.net, syzkaller-bugs@googlegroups.com, v9fs@lists.linux.dev Subject: Re: [syzbot] [v9fs?] KASAN: slab-use-after-free Write in v9fs_free_request 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-ID: <371418.1716375412.1@warthog.procyon.org.uk> Date: Wed, 22 May 2024 11:56:52 +0100 Message-ID: <371419.1716375412@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 asmadeus@codewreck.org wrote: > That's a tough one: netfs took a ref in v9fs_init_request (netfs op's > init_request) and expects to be able to use it until v9fs_free_request > (net op's free_request()), but the fs was dismounted first and we kill > the kmem cache at this point so we aggressively drop any dangling ref > there as there's no way of waiting. Which kmem cache are we talking about? I can see two in net/9p/ and one in fs/9p/. And took a ref on what? David