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 F060B3D5227 for ; Tue, 23 Jun 2026 14:54:03 +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=1782226445; cv=none; b=UDed/I9iNGOXRzsPtIjnK67FVt9wKlPph//+nSmxbWxht21+wIGZLsM7CQPQstvgvGLhOzp8TRFfbHc9iyu8afAenmiBMc2JqRrq814U55YT5vX7V+XS4kLpUcddHJOBK7tdU8CJsmJJ3NIh2uoMtajFdmqUO/NUWXN8f+3JVqY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782226445; c=relaxed/simple; bh=c70XTwAJzKyuNR6knoPrJL/ckuTGiXDPNfBF6DPn9zA=; h=From:In-Reply-To:References:To:Cc:Subject:MIME-Version: Content-Type:Date:Message-ID; b=ZYS9x9CvOp5mJ0sHbnbxmXEItZi38FGd/4TtfdnydLgQLz0OpXBNJZsraMGG0a0nVslx3Zhw+397wUOq45qFJoVPWcZagyaB9R7pAYAsc7fyOsoBZR8tjJL/YYoBk8OQdL+NZPhiki9tXWjsSFC8hWUGVhTZ3mhxYuBYzl1Tywg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=CqhAEHUW; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="CqhAEHUW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782226443; 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=EIBLs4b9hYj+9u/PkWZNtPRlc9DDx0+KA2+1Ck2RjNs=; b=CqhAEHUWUaMwyrc134iDgqcERI+iigjwLtIIwiPNMWKkMoTHvPCmKC7qmjVHW6jXlf+0la 6sfainnvJy5UjUXRakd5Vw7PNtPZv29BP31FFr+hqHoOXEfaQ32jlc7wMuJS/mvV/pujyl Vopdrl5Jhu7vhAKTQlt2fAmnKQSO1YI= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-306-Peeeg8DNNMipx1qbUp_h4g-1; Tue, 23 Jun 2026 10:53:59 -0400 X-MC-Unique: Peeeg8DNNMipx1qbUp_h4g-1 X-Mimecast-MFC-AGG-ID: Peeeg8DNNMipx1qbUp_h4g_1782226438 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7CFC4195607C; Tue, 23 Jun 2026 14:53:57 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.44.48.242]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 28AD51955F74; Tue, 23 Jun 2026 14:53:54 +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: To: hongao Cc: dhowells@redhat.com, Paulo Alcantara , netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+3c74b1f0c372e98efc32@syzkaller.appspotmail.com Subject: Re: [PATCH] netfs: Fix UAF in netfs_unbuffered_write() on failed preparation Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2877068.1782226433.1@warthog.procyon.org.uk> Date: Tue, 23 Jun 2026 15:53:53 +0100 Message-ID: <2877069.1782226433@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 hongao wrote: > /* Check if (re-)preparation failed. */ > if (unlikely(test_bit(NETFS_SREQ_FAILED, &subreq->flags))) { > - netfs_write_subrequest_terminated(subreq, subreq->error); > - wreq->error = subreq->error; > + ret = subreq->error; > + wreq->error = ret; > + netfs_write_subrequest_terminated(subreq, ret); > break; > } This shouldn't be effective as all netfs_write_subrequest_terminated() will do is pass control of the subreq struct back to the app thread. David