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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0BA5C6FA89 for ; Mon, 5 Sep 2022 07:22:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236658AbiIEHWd (ORCPT ); Mon, 5 Sep 2022 03:22:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236420AbiIEHVt (ORCPT ); Mon, 5 Sep 2022 03:21:49 -0400 Received: from corp-front07-corp.i.nease.net (corp-front07-corp.i.nease.net [59.111.134.157]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6514B40BCA; Mon, 5 Sep 2022 00:18:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=corp.netease.com; s=s210401; h=Received:From:To:Cc:Subject: Date:Message-Id:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=pgAPJwSQJ2munczLoGE8RAVrWa3OnIMrH9 iDbcBO1dU=; b=RyRwkg3N5yNTuvzSosygEZ/4H22agQQEyYfIEw3aQkAY+mxZGA ngBTJSDWa2myFI2CUOtI/8R6skDqBKk5m0P87IWgtSBkCD3gk9NZhX3nm7GdAPs3 BZiMuiUD/5vhsIukwGCi/zZPArlAIplEirKzzyAB4nAIuK070M6mpZYXM= Received: from pubt1-k8s74.yq.163.org (unknown [115.238.122.38]) by corp-front07-corp.i.nease.net (Coremail) with SMTP id nRDICgCX7OiyohVjhUwXAA--.50525S2; Mon, 05 Sep 2022 15:18:10 +0800 (HKT) From: liuyacan@corp.netease.com To: tonylu@linux.alibaba.com Cc: davem@davemloft.net, edumazet@google.com, kgraul@linux.ibm.com, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, liuyacan@corp.netease.com, netdev@vger.kernel.org, pabeni@redhat.com, ubraun@linux.vnet.ibm.com, wenjia@linux.ibm.com, wintera@linux.ibm.com Subject: Re: [PATCH net v4] net/smc: Fix possible access to freed memory in link clear Date: Mon, 5 Sep 2022 15:18:10 +0800 Message-Id: <20220905071810.2102474-1-liuyacan@corp.netease.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: nRDICgCX7OiyohVjhUwXAA--.50525S2 X-Coremail-Antispam: 1UD129KBjvJXoWxZF47GFWfCF4fur48GF4UJwb_yoWrAFy8pF WUKw47Cr4kXr1UXF4YyFyxAr1Uta1IyF48Grn2vr95CF15Gw1UJr1Igr17tFWkJr4qgryI yryvqw1xtrn8XaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUXIb7IF0VCFI7km07C26c804VAKzcIF0wAFF20E14v26r4j6ryU M7CY07I20VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2 IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84AC jcxK6xIIjxv20xvEc7CjxVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4 x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1ln4vE1TuYJxujqTIEc-sFP3VYkVW5Jr1DJw4U KVWUGwAawVACjsI_Ar4v6c8GOVW06r1DJrWUAwAawVACjsI_Ar4v6c8GOVWY6r1DJrWUAw AawVCFI7vE04vSzxk24VAqrcv_Gr1UXr18M2vj6xkI62vS6c8GOVWUtr1rJFyle2I262IY c4CY6c8Ij28IcVAaY2xG8wAqjxCE34x0Y48IcwAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxV A2Y2ka0xkIwI1lw4CEc2x0rVAKj4xxMx02cVAKzwCY0x0Ix7I2Y4AK64vIr41l42xK82IY c2Ij64vIr41l4x8a64kIII0Yj41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l4IxY624lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q 6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj TRMuWlUUUUU X-CM-SenderInfo: 5olx5txfdqquhrush05hwht23hof0z/1tbiBQAACVt771KQnwAEsa Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > > From: Yacan Liu > > > > After modifying the QP to the Error state, all RX WR would be completed > > with WC in IB_WC_WR_FLUSH_ERR status. Current implementation does not > > wait for it is done, but destroy the QP and free the link group directly. > > So there is a risk that accessing the freed memory in tasklet context. > > > > Here is a crash example: > > > > BUG: unable to handle page fault for address: ffffffff8f220860 > > #PF: supervisor write access in kernel mode > > #PF: error_code(0x0002) - not-present page > > PGD f7300e067 P4D f7300e067 PUD f7300f063 PMD 8c4e45063 PTE 800ffff08c9df060 > > Oops: 0002 [#1] SMP PTI > > CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: G S OE 5.10.0-0607+ #23 > > Hardware name: Inspur NF5280M4/YZMB-00689-101, BIOS 4.1.20 07/09/2018 > > RIP: 0010:native_queued_spin_lock_slowpath+0x176/0x1b0 > > Code: f3 90 48 8b 32 48 85 f6 74 f6 eb d5 c1 ee 12 83 e0 03 83 ee 01 48 c1 e0 05 48 63 f6 48 05 00 c8 02 00 48 03 04 f5 00 09 98 8e <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 32 > > RSP: 0018:ffffb3b6c001ebd8 EFLAGS: 00010086 > > RAX: ffffffff8f220860 RBX: 0000000000000246 RCX: 0000000000080000 > > RDX: ffff91db1f86c800 RSI: 000000000000173c RDI: ffff91db62bace00 > > RBP: ffff91db62bacc00 R08: 0000000000000000 R09: c00000010000028b > > R10: 0000000000055198 R11: ffffb3b6c001ea58 R12: ffff91db80e05010 > > R13: 000000000000000a R14: 0000000000000006 R15: 0000000000000040 > > FS: 0000000000000000(0000) GS:ffff91db1f840000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: ffffffff8f220860 CR3: 00000001f9580004 CR4: 00000000003706e0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > > > _raw_spin_lock_irqsave+0x30/0x40 > > mlx5_ib_poll_cq+0x4c/0xc50 [mlx5_ib] > > smc_wr_rx_tasklet_fn+0x56/0xa0 [smc] > > tasklet_action_common.isra.21+0x66/0x100 > > __do_softirq+0xd5/0x29c > > asm_call_irq_on_stack+0x12/0x20 > > > > do_softirq_own_stack+0x37/0x40 > > irq_exit_rcu+0x9d/0xa0 > > sysvec_call_function_single+0x34/0x80 > > asm_sysvec_call_function_single+0x12/0x20 > > > > Fixes: bd4ad57718cc ("smc: initialize IB transport incl. PD, MR, QP, CQ, event, WR") > > Signed-off-by: Yacan Liu > > > > --- > > Chagen in v4: > > -- Remove the rx_drain flag because smc_wr_rx_post() may not have been called. > > -- Remove timeout. > > Change in v3: > > -- Tune commit message (Signed-Off tag, Fixes tag). > > Tune code to avoid column length exceeding. > > Change in v2: > > -- Fix some compile warnings and errors. > > --- > > net/smc/smc_core.c | 2 ++ > > net/smc/smc_core.h | 2 ++ > > net/smc/smc_wr.c | 9 +++++++++ > > net/smc/smc_wr.h | 1 + > > 4 files changed, 14 insertions(+) > > > > diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c > > index ff49a11f5..f92a916e9 100644 > > --- a/net/smc/smc_core.c > > +++ b/net/smc/smc_core.c > > @@ -757,6 +757,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, > > lnk->lgr = lgr; > > smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */ > > lnk->link_idx = link_idx; > > + lnk->wr_rx_id_compl = 0; > > smc_ibdev_cnt_inc(lnk); > > smcr_copy_dev_info_to_link(lnk); > > atomic_set(&lnk->conn_cnt, 0); > > @@ -1269,6 +1270,7 @@ void smcr_link_clear(struct smc_link *lnk, bool log) > > smcr_buf_unmap_lgr(lnk); > > smcr_rtoken_clear_link(lnk); > > smc_ib_modify_qp_error(lnk); > > + smc_wr_drain_cq(lnk); > > smc_wr_drain_cq() can put into smc_wr_free_link(). Since > smc_wr_free_link() do the same things together, such as waiting for > resources cleaning up about wr. > > > smc_wr_free_link(lnk); > > smc_ib_destroy_queue_pair(lnk); > > smc_ib_dealloc_protection_domain(lnk); > > > > The patch tested good in our environment. If you are going to send the > v5 patch, you can go with my review. > > Reviewed-by: Tony Lu > > Cheers, > Tony Lu Thank you very much for your verification and suggestion! Regards, Yacan