From patchwork Wed Dec 1 03:02:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dust Li X-Patchwork-Id: 12648951 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6253C433F5 for ; Wed, 1 Dec 2021 03:02:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346373AbhLADGD (ORCPT ); Tue, 30 Nov 2021 22:06:03 -0500 Received: from out4436.biz.mail.alibaba.com ([47.88.44.36]:63893 "EHLO out4436.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346365AbhLADGD (ORCPT ); Tue, 30 Nov 2021 22:06:03 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R621e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=dust.li@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0UywMJZt_1638327750; Received: from localhost(mailfrom:dust.li@linux.alibaba.com fp:SMTPD_---0UywMJZt_1638327750) by smtp.aliyun-inc.com(127.0.0.1); Wed, 01 Dec 2021 11:02:30 +0800 From: Dust Li To: Karsten Graul , "David S . Miller" , Jakub Kicinski , Ursula Braun Cc: Tony Lu , Wen Gu , linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH net v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early Date: Wed, 1 Dec 2021 11:02:30 +0800 Message-Id: <20211201030230.8896-1-dust.li@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.3.ge56e4f7 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org smc_lgr_cleanup_early() meant to delete the link group from the link group list, but it deleted the list head by mistake. This may cause memory corruption since we didn't remove the real link group from the list and later memseted the link group structure. We got a list corruption panic when testing: [  231.277259] list_del corruption. prev->next should be ffff8881398a8000, but was 0000000000000000 [  231.278222] ------------[ cut here ]------------ [  231.278726] kernel BUG at lib/list_debug.c:53! [  231.279326] invalid opcode: 0000 [#1] SMP NOPTI [  231.279803] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.10.46+ #435 [  231.280466] Hardware name: Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014 [  231.281248] Workqueue: events smc_link_down_work [  231.281732] RIP: 0010:__list_del_entry_valid+0x70/0x90 [  231.282258] Code: 4c 60 82 e8 7d cc 6a 00 0f 0b 48 89 fe 48 c7 c7 88 4c 60 82 e8 6c cc 6a 00 0f 0b 48 89 fe 48 c7 c7 c0 4c 60 82 e8 5b cc 6a 00 <0f> 0b 48 89 fe 48 c7 c7 00 4d 60 82 e8 4a cc 6a 00 0f 0b cc cc cc [  231.284146] RSP: 0018:ffffc90000033d58 EFLAGS: 00010292 [  231.284685] RAX: 0000000000000054 RBX: ffff8881398a8000 RCX: 0000000000000000 [  231.285415] RDX: 0000000000000001 RSI: ffff88813bc18040 RDI: ffff88813bc18040 [  231.286141] RBP: ffffffff8305ad40 R08: 0000000000000003 R09: 0000000000000001 [  231.286873] R10: ffffffff82803da0 R11: ffffc90000033b90 R12: 0000000000000001 [  231.287606] R13: 0000000000000000 R14: ffff8881398a8000 R15: 0000000000000003 [  231.288337] FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 [  231.289160] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [  231.289754] CR2: 0000000000e72058 CR3: 000000010fa96006 CR4: 00000000003706f0 [  231.290485] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [  231.291211] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [  231.291940] Call Trace: [  231.292211]  smc_lgr_terminate_sched+0x53/0xa0 [  231.292677]  smc_switch_conns+0x75/0x6b0 [  231.293085]  ? update_load_avg+0x1a6/0x590 [  231.293517]  ? ttwu_do_wakeup+0x17/0x150 [  231.293907]  ? update_load_avg+0x1a6/0x590 [  231.294317]  ? newidle_balance+0xca/0x3d0 [  231.294716]  smcr_link_down+0x50/0x1a0 [  231.295090]  ? __wake_up_common_lock+0x77/0x90 [  231.295534]  smc_link_down_work+0x46/0x60 [  231.295933]  process_one_work+0x18b/0x350 Fixes: a0a62ee15a829 ("net/smc: separate locks for SMCD and SMCR link group lists") Signed-off-by: Dust Li Acked-by: Karsten Graul Reviewed-by: Tony Lu --- v2: Remove unused lgr_list v2->v3: Fix uninitialized lgr_lock, thanks Jakub Kicinski ! --- net/smc/smc_core.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index bb52c8b5f148..387d28b2f8dd 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -625,18 +625,17 @@ int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb) void smc_lgr_cleanup_early(struct smc_connection *conn) { struct smc_link_group *lgr = conn->lgr; - struct list_head *lgr_list; spinlock_t *lgr_lock; if (!lgr) return; smc_conn_free(conn); - lgr_list = smc_lgr_list_head(lgr, &lgr_lock); + smc_lgr_list_head(lgr, &lgr_lock); spin_lock_bh(lgr_lock); /* do not use this link group for new connections */ - if (!list_empty(lgr_list)) - list_del_init(lgr_list); + if (!list_empty(&lgr->list)) + list_del_init(&lgr->list); spin_unlock_bh(lgr_lock); __smc_lgr_terminate(lgr, true); }