From patchwork Wed Sep 5 08:00:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominique Martinet X-Patchwork-Id: 966248 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=codewreck.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 424x330Qhsz9s7T for ; Wed, 5 Sep 2018 18:00:47 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727794AbeIEM3j (ORCPT ); Wed, 5 Sep 2018 08:29:39 -0400 Received: from nautica.notk.org ([91.121.71.147]:36893 "EHLO nautica.notk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725865AbeIEM3j (ORCPT ); Wed, 5 Sep 2018 08:29:39 -0400 Received: by nautica.notk.org (Postfix, from userid 1001) id 433EEC009; Wed, 5 Sep 2018 10:00:38 +0200 (CEST) From: Dominique Martinet To: Dominique Martinet , Eric Van Hensbergen , Latchesar Ionkov Cc: Gertjan Halkes , v9fs-developer@lists.sourceforge.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Dominique Martinet Subject: [PATCH] 9p: readdir: do not trust pdu content for stat item size Date: Wed, 5 Sep 2018 10:00:32 +0200 Message-Id: <1536134432-11997-1-git-send-email-asmadeus@codewreck.org> X-Mailer: git-send-email 1.7.10.4 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Gertjan Halkes v9fs_dir_readdir() could deadloop if a struct was sent with a size set to -2 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88021 Signed-off-by: Gertjan Halkes Signed-off-by: Dominique Martinet --- This patch has been sitting in bugzilla for three years, I'll take it for the next merge window after some testing. Thanks Gertjan! fs/9p/vfs_dir.c | 8 +++----- net/9p/protocol.c | 3 ++- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c index 48db9a9f13f9..cb6c4031af55 100644 --- a/fs/9p/vfs_dir.c +++ b/fs/9p/vfs_dir.c @@ -105,7 +105,6 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) int err = 0; struct p9_fid *fid; int buflen; - int reclen = 0; struct p9_rdir *rdir; struct kvec kvec; @@ -138,11 +137,10 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) while (rdir->head < rdir->tail) { err = p9stat_read(fid->clnt, rdir->buf + rdir->head, rdir->tail - rdir->head, &st); - if (err) { + if (err <= 0) { p9_debug(P9_DEBUG_VFS, "returned %d\n", err); return -EIO; } - reclen = st.size+2; over = !dir_emit(ctx, st.name, strlen(st.name), v9fs_qid2ino(&st.qid), dt_type(&st)); @@ -150,8 +148,8 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) if (over) return 0; - rdir->head += reclen; - ctx->pos += reclen; + rdir->head += err; + ctx->pos += err; } } } diff --git a/net/9p/protocol.c b/net/9p/protocol.c index ee32bbf12675..b4d80c533f89 100644 --- a/net/9p/protocol.c +++ b/net/9p/protocol.c @@ -571,9 +571,10 @@ int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st) if (ret) { p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret); trace_9p_protocol_dump(clnt, &fake_pdu); + return ret; } - return ret; + return fake_pdu.offset; } EXPORT_SYMBOL(p9stat_read);