From patchwork Fri Jan 17 16:32:58 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olga Kornievskaia X-Patchwork-Id: 13943579 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 1215819F47E for ; Fri, 17 Jan 2025 16:33:09 +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=1737131591; cv=none; b=iJhehS4oJUBjk3WTZmPtdi4wxo262QaWwyfxhacS7npesEjkXk7VLq+qPa+xb/hAync8LeIDMiA2bA696ewDpAIRUu5WdELG4N1KNpDEFaWooysVADEa9XaNh3Gv+HofIgMy865RSW3QgNCn+AY8v0dl99igLFC27Qbl7yZ3E70= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737131591; c=relaxed/simple; bh=HK/4/ppyD9uqNCngbCzJRIR/OgIbDfMbmy/xryrtbIE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=Ciq6RS4z8RaewZ7+K0a2+Yb/ifBUvUbzy7sfJ2fxbGrmCc9rp+KEf9ztsfmAwIxSrKQmHoExIV84KDVCslZy1gQ90UvMRM2uqVEOnX6YramKfat5EU47HPH6B/aPNuonEmmubwWYBqm7j8/sbQp12ZjIAnexV8+5eHii0gaa28w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=jQY2dVOU; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="jQY2dVOU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737131589; 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; bh=Ru/vwkeKSjgJVRnD/6xHjyd9VAusIrSoT64KJaSDug8=; b=jQY2dVOUT83BRzNtAxJAgcYd2m9Y+d1zugA26ln8flZE4Q3hxEeAbEHwJ7kacJnp92dcaa jD1+MDPQP+/X28PUwbgbdsiZurzYTEadtA0Sm7QkUVLY2FQjIA7b9iStSYSjp/8PVoBjt9 XN7Inl/Az9RPUUwES6Hx892yTooYfhU= Received: from mx-prod-mc-04.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-247-moywrpHUOaCGY8eJ7-CvkA-1; Fri, 17 Jan 2025 11:33:04 -0500 X-MC-Unique: moywrpHUOaCGY8eJ7-CvkA-1 X-Mimecast-MFC-AGG-ID: moywrpHUOaCGY8eJ7-CvkA Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4C3201955D4E; Fri, 17 Jan 2025 16:33:03 +0000 (UTC) Received: from okorniev-mac.redhat.com (unknown [10.22.89.195]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 9D37E19560A3; Fri, 17 Jan 2025 16:33:01 +0000 (UTC) From: Olga Kornievskaia To: chuck.lever@oracle.com, jlayton@kernel.org Cc: linux-nfs@vger.kernel.org, neilb@suse.de, Dai.Ngo@oracle.com, tom@talpey.com, Olga Kornievskaia Subject: [PATCH 1/1] nfsd: fix management of listener transports Date: Fri, 17 Jan 2025 11:32:58 -0500 Message-Id: <20250117163258.52885-1-okorniev@redhat.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Currently, when no active threads are running, a root user using nfsdctl command can try to remove a particular listener from the list of previously added ones, then start the server by increasing the number of threads, it leads to the following problem: [ 158.835354] refcount_t: addition on 0; use-after-free. [ 158.835603] WARNING: CPU: 2 PID: 9145 at lib/refcount.c:25 refcount_warn_saturate+0x160/0x1a0 [ 158.836017] Modules linked in: rpcrdma rdma_cm iw_cm ib_cm ib_core nfsd auth_rpcgss nfs_acl lockd grace overlay isofs uinput snd_seq_dummy snd_hrtimer nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables qrtr sunrpc vfat fat uvcvideo videobuf2_vmalloc videobuf2_memops uvc videobuf2_v4l2 videodev videobuf2_common snd_hda_codec_generic mc e1000e snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore sg loop dm_multipath dm_mod nfnetlink vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vmw_vmci vsock xfs libcrc32c crct10dif_ce ghash_ce vmwgfx sha2_ce sha256_arm64 sr_mod sha1_ce cdrom nvme drm_client_lib drm_ttm_helper ttm nvme_core drm_kms_helper nvme_auth drm fuse [ 158.840093] CPU: 2 UID: 0 PID: 9145 Comm: nfsd Kdump: loaded Tainted: G B W 6.13.0-rc6+ #7 [ 158.840624] Tainted: [B]=BAD_PAGE, [W]=WARN [ 158.840802] Hardware name: VMware, Inc. VMware20,1/VBSA, BIOS VMW201.00V.24006586.BA64.2406042154 06/04/2024 [ 158.841220] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 158.841563] pc : refcount_warn_saturate+0x160/0x1a0 [ 158.841780] lr : refcount_warn_saturate+0x160/0x1a0 [ 158.842000] sp : ffff800089be7d80 [ 158.842147] x29: ffff800089be7d80 x28: ffff00008e68c148 x27: ffff00008e68c148 [ 158.842492] x26: ffff0002e3b5c000 x25: ffff600011cd1829 x24: ffff00008653c010 [ 158.842832] x23: ffff00008653c000 x22: 1fffe00011cd1829 x21: ffff00008653c028 [ 158.843175] x20: 0000000000000002 x19: ffff00008653c010 x18: 0000000000000000 [ 158.843505] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 158.843836] x14: 0000000000000000 x13: 0000000000000001 x12: ffff600050a26493 [ 158.844143] x11: 1fffe00050a26492 x10: ffff600050a26492 x9 : dfff800000000000 [ 158.844475] x8 : 00009fffaf5d9b6e x7 : ffff000285132493 x6 : 0000000000000001 [ 158.844823] x5 : ffff000285132490 x4 : ffff600050a26493 x3 : ffff8000805e72bc [ 158.845174] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000098588000 [ 158.845528] Call trace: [ 158.845658] refcount_warn_saturate+0x160/0x1a0 (P) [ 158.845894] svc_recv+0x58c/0x680 [sunrpc] [ 158.846183] nfsd+0x1fc/0x348 [nfsd] [ 158.846390] kthread+0x274/0x2f8 [ 158.846546] ret_from_fork+0x10/0x20 [ 158.846714] ---[ end trace 0000000000000000 ]--- nfsd_nl_listener_set_doit() would manipulate the list of transports of server's sv_permsocks and close the specified listener but the other list of transports (server's sp_xprts list) would not be changed leading to the problem above. Instead, determined if the nfsdctl is trying to remove a listener, in which case, delete all the existing listener transports and re-create all-but-the-removed ones. Fixes: 16a471177496 ("NFSD: add listener-{set,get} netlink command") Signed-off-by: Olga Kornievskaia Reviewed-by: Jeff Layton --- fs/nfsd/nfsctl.c | 41 ++++++++++++++++++----------------------- 1 file changed, 18 insertions(+), 23 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 95ea4393305b..079c1fe2eee7 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1918,6 +1918,7 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) LIST_HEAD(permsocks); struct nfsd_net *nn; int err, rem; + bool delete = false; mutex_lock(&nfsd_mutex); @@ -1977,35 +1978,26 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) } } - /* For now, no removing old sockets while server is running */ - if (serv->sv_nrthreads && !list_empty(&permsocks)) { + /* If we have listener transports left on permsocks list, it means + * we are asked to remove a listener + */ + if (!list_empty(&permsocks)) { list_splice_init(&permsocks, &serv->sv_permsocks); - spin_unlock_bh(&serv->sv_lock); - err = -EBUSY; - goto out_unlock_mtx; + delete = true; } + spin_unlock_bh(&serv->sv_lock); - /* Close the remaining sockets on the permsocks list */ - while (!list_empty(&permsocks)) { - xprt = list_first_entry(&permsocks, struct svc_xprt, xpt_list); - list_move(&xprt->xpt_list, &serv->sv_permsocks); - - /* - * Newly-created sockets are born with the BUSY bit set. Clear - * it if there are no threads, since nothing can pick it up - * in that case. + /* Not removing old listener transports while server is running */ + if (serv->sv_nrthreads) { + err = -EBUSY; + goto out_unlock_mtx; + } else if (delete) { + /* since we can't delete a single entry, we will destroy + * all remaining listeners and recreate the list */ - if (!serv->sv_nrthreads) - clear_bit(XPT_BUSY, &xprt->xpt_flags); - - set_bit(XPT_CLOSE, &xprt->xpt_flags); - spin_unlock_bh(&serv->sv_lock); - svc_xprt_close(xprt); - spin_lock_bh(&serv->sv_lock); + svc_xprt_destroy_all(serv, net); } - spin_unlock_bh(&serv->sv_lock); - /* walk list of addrs again, open any that still don't exist */ nlmsg_for_each_attr(attr, info->nlhdr, GENL_HDRLEN, rem) { struct nlattr *tb[NFSD_A_SOCK_MAX + 1]; @@ -2031,6 +2023,9 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) xprt = svc_find_listener(serv, xcl_name, net, sa); if (xprt) { + if (delete) + WARN_ONCE("Transport type=%s already exists\n", + xcl_name); svc_xprt_put(xprt); continue; }