From patchwork Thu Feb 13 14:42:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Lingfeng X-Patchwork-Id: 13973332 X-Patchwork-Delegate: cel@kernel.org Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) (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 B497028135A; Thu, 13 Feb 2025 14:24:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.35 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739456701; cv=none; b=ljupW9drqhhi5OCWiaDn3lYU+Y+W/egoY2sXnFU3vkDZPlHB7MSiF6Bq7X6d8OTpXUKpLSyMwn1bz6VwvK/6Any20/vwP1RjLS3/mQ9cgdp2XjVQ+HS3HJ3ZE35SdZwP5rLidqX+4rONW2asiPzHR7NWSzq4vYERNvMbRTqP49w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739456701; c=relaxed/simple; bh=xnzELmoh7abzL9m1IEvTPPrap/skeMH5SYaGFuCx6PY=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=RNhmNITmVdyOlCAWlMs0JVNLcqjpIppydx1I6ds/m9O9kkNMM3bus1MWDnjlQBzwLwI3/+T65oArW9QOynI7c+xydZN8EqDEVLQmdxJtJ2fFD2st1pYIp+9kvZa5YFwzJufcBZpfB0c/qIpDySY+lDBhOS5dc+x/XF9mswrfO3g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.35 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4Yty5w4H8Vz1V6S6; Thu, 13 Feb 2025 22:21:08 +0800 (CST) Received: from kwepemg500017.china.huawei.com (unknown [7.202.181.81]) by mail.maildlp.com (Postfix) with ESMTPS id 82E18140202; Thu, 13 Feb 2025 22:24:56 +0800 (CST) Received: from huawei.com (10.175.127.227) by kwepemg500017.china.huawei.com (7.202.181.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 13 Feb 2025 22:24:55 +0800 From: Li Lingfeng To: , , , , , , , CC: , , , , , Subject: [PATCH v2] nfsd: put dl_stid if fail to queue dl_recall Date: Thu, 13 Feb 2025 22:42:20 +0800 Message-ID: <20250213144220.156089-1-lilingfeng3@huawei.com> X-Mailer: git-send-email 2.31.1 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemg500017.china.huawei.com (7.202.181.81) Before calling nfsd4_run_cb to queue dl_recall to the callback_wq, we increment the reference count of dl_stid. We expect that after the corresponding work_struct is processed, the reference count of dl_stid will be decremented through the callback function nfsd4_cb_recall_release. However, if the call to nfsd4_run_cb fails, the incremented reference count of dl_stid will not be decremented correspondingly, leading to the following nfs4_stid leak: unreferenced object 0xffff88812067b578 (size 344): comm "nfsd", pid 2761, jiffies 4295044002 (age 5541.241s) hex dump (first 32 bytes): 01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff ....kkkk........ 00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .kkkkkkk.....N.. backtrace: kmem_cache_alloc+0x4b9/0x700 nfsd4_process_open1+0x34/0x300 nfsd4_open+0x2d1/0x9d0 nfsd4_proc_compound+0x7a2/0xe30 nfsd_dispatch+0x241/0x3e0 svc_process_common+0x5d3/0xcc0 svc_process+0x2a3/0x320 nfsd+0x180/0x2e0 kthread+0x199/0x1d0 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1b/0x30 unreferenced object 0xffff8881499f4d28 (size 368): comm "nfsd", pid 2761, jiffies 4295044005 (age 5541.239s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff ........0M.I.... 30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00 0M.I.... ....... backtrace: kmem_cache_alloc+0x4b9/0x700 nfs4_alloc_stid+0x29/0x210 alloc_init_deleg+0x92/0x2e0 nfs4_set_delegation+0x284/0xc00 nfs4_open_delegation+0x216/0x3f0 nfsd4_process_open2+0x2b3/0xee0 nfsd4_open+0x770/0x9d0 nfsd4_proc_compound+0x7a2/0xe30 nfsd_dispatch+0x241/0x3e0 svc_process_common+0x5d3/0xcc0 svc_process+0x2a3/0x320 nfsd+0x180/0x2e0 kthread+0x199/0x1d0 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1b/0x30 Fix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if fail to queue dl_recall. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Li Lingfeng Reviewed-by: Jeff Layton --- Changes in v2: - Add a comment to nfs4_free_deleg. --- fs/nfsd/nfs4state.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 153eeea2c7c9..d442d61e2947 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1050,6 +1050,12 @@ static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp) return openlockstateid(stid); } +/* + * As the sc_free callback of deleg, this may be called by nfs4_put_stid + * in nfsd_break_one_deleg. + * Considering nfsd_break_one_deleg is called with the flc->flc_lock held, + * this function mustn't ever sleep. + */ static void nfs4_free_deleg(struct nfs4_stid *stid) { struct nfs4_delegation *dp = delegstateid(stid); @@ -5414,6 +5420,7 @@ static const struct nfsd4_callback_ops nfsd4_cb_recall_ops = { static void nfsd_break_one_deleg(struct nfs4_delegation *dp) { + bool queued; /* * We're assuming the state code never drops its reference * without first removing the lease. Since we're in this lease @@ -5422,7 +5429,10 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp) * we know it's safe to take a reference. */ refcount_inc(&dp->dl_stid.sc_count); - WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall)); + queued = nfsd4_run_cb(&dp->dl_recall); + WARN_ON_ONCE(!queued); + if (!queued) + nfs4_put_stid(&dp->dl_stid); } /* Called from break_lease() with flc_lock held. */