From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 16B3C429019 for ; Mon, 10 Aug 2026 14:51:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786373480; cv=none; b=C0bgkzU7Wdf2bxYBKA2DB9w4yuMdprxwLNxgYFj2iWw3ntbid/UVcDioCkfI65ahlSzTU9+EJCBDnVqqH8EShIEM5AURIJHK8CMj93PXXn89ddVJqSwwVbpL78tdcTbCHPl5hW9d+Exuc90mOiNi38UvO38GRrOjZEgEaQKkICs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786373480; c=relaxed/simple; bh=b5klDRZS7/MjzMV2m5pL2fGfwg19hAIiZ5TPF58XIGQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gx0HOGI0yhFSPxqD+aHxGONiACTtswKGWONKlvafKkZMScSBw7h5AhQl18/ZT1Oqc2wrk5rh2JRkIJu+xpvK5LMb4R2gs01mhhCKEqLRoVhelWJ9da8y6uBLdYX9XbVz06wWUFa4OSUKSNM/u4NSUFTDxHMfwr3UUzKBkocRLko= 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=fgML6S9z; arc=none smtp.client-ip=170.10.129.124 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="fgML6S9z" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1786373478; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WpRWdWQ2o2csTkSLqj2j6GymBuhovuv+4XkP7R//hNk=; b=fgML6S9z/ZiNhjGGJDoyRmNg867VlqibB+vlK+VaO6djEDHy+KREtOgg+f+XqWK/PVEXMN WxOnkvSqZ0tyyseVSA5bXA7LECjO12RKj0BvF99EawUPt5gT9YHtHmR2R1lHICAe9dxLfx ovzQzTb4QfvDBrIPx0MMghNecsBoIaI= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-623-BOOmvZM4Oo-IXxWzXkFNKQ-1; Mon, 10 Aug 2026 10:51:12 -0400 X-MC-Unique: BOOmvZM4Oo-IXxWzXkFNKQ-1 X-Mimecast-MFC-AGG-ID: BOOmvZM4Oo-IXxWzXkFNKQ_1786373469 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BCCB618001E3; Mon, 10 Aug 2026 14:51:09 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.44.32.44]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 14659426; Mon, 10 Aug 2026 14:51:03 +0000 (UTC) From: David Howells To: Christian Brauner , Matthew Wilcox , Christoph Hellwig Cc: David Howells , Paulo Alcantara , Jens Axboe , Leon Romanovsky , Steve French , ChenXiaoSong , Marc Dionne , Stefan Metzmacher , Eric Van Hensbergen , Dominique Martinet , Ilya Dryomov , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 24/26] netfs: Check for too much data being read Date: Mon, 10 Aug 2026 15:47:41 +0100 Message-ID: <20260810144746.574036-25-dhowells@redhat.com> In-Reply-To: <20260810144746.574036-1-dhowells@redhat.com> References: <20260810144746.574036-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 Put in a check in read subreq termination to detect more data being read for a subrequest than was requested. In the event that this happens, abort the rest of the read request on the basis that some of the read buffer may have been corrupted and return -EIO. Signed-off-by: David Howells cc: Paulo Alcantara cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org --- fs/netfs/read_collect.c | 23 +++++++++++++++++++++++ include/trace/events/netfs.h | 1 + 2 files changed, 24 insertions(+) diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index cf7c36037edc..21eb7f74d66e 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -307,6 +307,14 @@ static void netfs_collect_read_results(struct netfs_io_request *rreq) notes |= HIT_PENDING; transferred = READ_ONCE(front->transferred); + if (unlikely(transferred > front->len)) { + /* Ugh... A subreq overran its allotted length. It + * may have corrupted the read buffer. + */ + stream->error = -EIO; + stream->failed = true; + goto abandon_request; + } /* If we can collect the next folio from a pending op, do so, * but we should only do it if we don't otherwise need to wait @@ -627,6 +635,21 @@ void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq) break; } + /* If the subrequest read more than it was supposed to, abort + * the request with EIO as we may have clobbered other parts + * of the buffer that are already read. + */ + if (subreq->transferred > subreq->len) { + trace_netfs_sreq(subreq, netfs_sreq_trace_too_much); + __set_bit(NETFS_SREQ_FAILED, &subreq->flags); + __clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); + subreq->error = -EIO; + trace_netfs_failure(rreq, subreq, subreq->error, netfs_fail_read); + trace_netfs_rreq(rreq, netfs_rreq_trace_set_pause); + set_bit(NETFS_RREQ_PAUSE, &rreq->flags); + goto skip_error_checks; + } + /* Deal with retry requests, short reads and errors. If we retry * but don't make progress, we abandon the attempt. */ diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h index 071d20e80f13..723cb7315308 100644 --- a/include/trace/events/netfs.h +++ b/include/trace/events/netfs.h @@ -132,6 +132,7 @@ EM(netfs_sreq_trace_submit, "SUBMT") \ EM(netfs_sreq_trace_superfluous, "SPRFL") \ EM(netfs_sreq_trace_terminated, "TERM ") \ + EM(netfs_sreq_trace_too_much, "!TOOM") \ EM(netfs_sreq_trace_wait_for, "_WAIT") \ EM(netfs_sreq_trace_write, "WRITE") \ EM(netfs_sreq_trace_write_skip, "SKIP ") \