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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD7C6C48BD3 for ; Thu, 27 Jun 2019 00:35:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B53FF217F4 for ; Thu, 27 Jun 2019 00:35:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561595750; bh=ozNMpS8bpFGjzEslo1XHCm1rR2P1bHb1+IRkhfR11mE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vpKFITBBZU4YJFJCoSSbDn8BazjBncO2Bz7roilhAgnpzaqwxy/GslXj8rvbYTpHi iWImqIhzJsO/hENDjZyF+4prfnSz9xpoLvQwI7K9H9whdrYtXUGcKHN6gIV3gpHFuw y9K2F8s3FKaAOj0shl6HDN4NSXavPAvMUusC+IMM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728274AbfF0AfW (ORCPT ); Wed, 26 Jun 2019 20:35:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:39788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728252AbfF0AfV (ORCPT ); Wed, 26 Jun 2019 20:35:21 -0400 Received: from sasha-vm.mshome.net (unknown [107.242.116.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 776BA21851; Thu, 27 Jun 2019 00:35:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561595720; bh=ozNMpS8bpFGjzEslo1XHCm1rR2P1bHb1+IRkhfR11mE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L7/IyaCxj/M+h7ePrpk0Fqp/5KMgcVZ4Gm1tytz6jzq2TuxAOOx0f4cSw84L8sdsO /d8YwcbURuGJtYg+8If6cNZ67tBkvB5F08Y6QRRDtHEYVNFczCnyFfgg67jVGoaaEd kmtTMSuHyuGTViz/EETtCTJ8qsiuuhWArVoef6Co= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Amir Goldstein , syzbot+c277e8e2f46414645508@syzkaller.appspotmail.com, Jan Kara , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 5.1 91/95] fanotify: update connector fsid cache on add mark Date: Wed, 26 Jun 2019 20:30:16 -0400 Message-Id: <20190627003021.19867-91-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190627003021.19867-1-sashal@kernel.org> References: <20190627003021.19867-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Amir Goldstein [ Upstream commit c285a2f01d692ef48d7243cf1072897bbd237407 ] When implementing connector fsid cache, we only initialized the cache when the first mark added to object was added by FAN_REPORT_FID group. We forgot to update conn->fsid when the second mark is added by FAN_REPORT_FID group to an already attached connector without fsid cache. Reported-and-tested-by: syzbot+c277e8e2f46414645508@syzkaller.appspotmail.com Fixes: 77115225acc6 ("fanotify: cache fsid in fsnotify_mark_connector") Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/notify/fanotify/fanotify.c | 4 ++++ fs/notify/mark.c | 14 +++++++++++--- include/linux/fsnotify_backend.h | 4 +++- 3 files changed, 18 insertions(+), 4 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 63c6bb1f8c4d..8c286f8228e5 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -355,6 +355,10 @@ static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info) /* Mark is just getting destroyed or created? */ if (!conn) continue; + if (!(conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID)) + continue; + /* Pairs with smp_wmb() in fsnotify_add_mark_list() */ + smp_rmb(); fsid = conn->fsid; if (WARN_ON_ONCE(!fsid.val[0] && !fsid.val[1])) continue; diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 22acb0a79b53..e9d49191d39e 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -495,10 +495,13 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, conn->type = type; conn->obj = connp; /* Cache fsid of filesystem containing the object */ - if (fsid) + if (fsid) { conn->fsid = *fsid; - else + conn->flags = FSNOTIFY_CONN_FLAG_HAS_FSID; + } else { conn->fsid.val[0] = conn->fsid.val[1] = 0; + conn->flags = 0; + } if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) inode = igrab(fsnotify_conn_inode(conn)); /* @@ -573,7 +576,12 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark, if (err) return err; goto restart; - } else if (fsid && (conn->fsid.val[0] || conn->fsid.val[1]) && + } else if (fsid && !(conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID)) { + conn->fsid = *fsid; + /* Pairs with smp_rmb() in fanotify_get_fsid() */ + smp_wmb(); + conn->flags |= FSNOTIFY_CONN_FLAG_HAS_FSID; + } else if (fsid && (conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID) && (fsid->val[0] != conn->fsid.val[0] || fsid->val[1] != conn->fsid.val[1])) { /* diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 094b38f2d9a1..0f67cabbbec8 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -292,7 +292,9 @@ typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t; */ struct fsnotify_mark_connector { spinlock_t lock; - unsigned int type; /* Type of object [lock] */ + unsigned short type; /* Type of object [lock] */ +#define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01 + unsigned short flags; /* flags [lock] */ __kernel_fsid_t fsid; /* fsid of filesystem containing object */ union { /* Object pointer [lock] */ -- 2.20.1