From patchwork Tue Aug 30 03:05:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: liuyacan@corp.netease.com X-Patchwork-Id: 12958639 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 7C738C0502C for ; Tue, 30 Aug 2022 03:06:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229914AbiH3DGU (ORCPT ); Mon, 29 Aug 2022 23:06:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229616AbiH3DGO (ORCPT ); Mon, 29 Aug 2022 23:06:14 -0400 Received: from corp-front10-corp.i.nease.net (corp-front10-corp.i.nease.net [42.186.62.104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34D49719AE; Mon, 29 Aug 2022 20:06:10 -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=t3d3QDx9C7aIcp4M1C7MLhQ4SK+SUL7FV2 hnpYAOk3I=; b=LR30vbc5BZnNsZru+Flv7CXkxEW2W5qYavspG3psLJsF6z6aEk 2O4eVRaEBxVhGn6Ze2AjX1wiviFMzoDGPwKdTlnFfBP5hZCfl3tiFb59yiasPHaQ F87ZxQYgdWgoIkGulSsJWfmEeontRp+clrJAbnrv5t8eAvNV6Nr38k5v0= Received: from pubt1-k8s74.yq.163.org (unknown [115.238.122.38]) by corp-front10-corp.i.nease.net (Coremail) with SMTP id aIG_CgDn0eSVfg1jEmwgAA--.1668S2; Tue, 30 Aug 2022 11:05:57 +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, wenjia@linux.ibm.com Subject: [PATCH net v2] net/smc: Fix possible access to freed memory in link clear Date: Tue, 30 Aug 2022 11:05:55 +0800 Message-Id: <20220830030555.373860-1-liuyacan@corp.netease.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 X-CM-TRANSID: aIG_CgDn0eSVfg1jEmwgAA--.1668S2 X-Coremail-Antispam: 1UD129KBjvJXoW3ArWUXrWDuF4rtr4kAr45Awb_yoWxJF17pF W7Gr1xCr48Xr1kWF1kCFyUZ3W5t3W2kF1rG34avr95ZFnrGw18tF1Sqr12vFW5JF4qga4I vrW8Xw1Ikrn8JaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUL0b7IF0VCFI7km07C26c804VAKzcIF0wAFF20E14v26r4j6ryU M7CY07I20VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2 IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84AC jcxK6xIIjxv20xvEc7CjxVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4 x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1ln4vE1TuYJxujqTIEc-sFP3VYkVW5Jr1DJw4U KVWUGwAawVCFI7vE04vSzxk24VAqrcv_Gr1UXr18M2AIxVAIcxkEcVAq07x20xvEncxIr2 1l57IF6s8CjcxG0xyl5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j 6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04v7M4kE6xkI j40Ew7xC0wCjxxvEw4Wlc2IjII80xcxEwVAKI48JMxAIw28IcxkI7VAKI48JMxCjnVAK0I I2c7xJMxC20s026xCaFVCjc4AY6r1j6r4UMxCIbVAxMI8I3I0E5I8CrVAFwI0_Jr0_Jr4l x2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrw CI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI 42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z2 80aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7sRiE_M7UUUUU== X-CM-SenderInfo: 5olx5txfdqquhrush05hwht23hof0z/1tbiBQAOCVt77xBV+AACsy Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: liuyacan 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 free the link directly. So there is a risk that accessing the freed link 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 Signed-off-by: liuyacan --- net/smc/smc_core.c | 2 ++ net/smc/smc_core.h | 2 ++ net/smc/smc_wr.c | 12 ++++++++++++ net/smc/smc_wr.h | 3 +++ 4 files changed, 19 insertions(+) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index ff49a11f5..b632a33f1 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -752,6 +752,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, atomic_inc(&lnk->smcibdev->lnk_cnt); refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */ lnk->clearing = 0; + lnk->rx_drained = 0; lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu; lnk->link_id = smcr_next_link_id(lgr); lnk->lgr = lgr; @@ -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_free_link(lnk); smc_ib_destroy_queue_pair(lnk); smc_ib_dealloc_protection_domain(lnk); diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index fe8b524ad..0a469a3e7 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -117,6 +117,7 @@ struct smc_link { u64 wr_rx_id; /* seq # of last recv WR */ u32 wr_rx_cnt; /* number of WR recv buffers */ unsigned long wr_rx_tstamp; /* jiffies when last buf rx */ + wait_queue_head_t wr_rx_drain_wait; /* wait for WR drain */ struct ib_reg_wr wr_reg; /* WR register memory region */ wait_queue_head_t wr_reg_wait; /* wait for wr_reg result */ @@ -138,6 +139,7 @@ struct smc_link { u8 link_idx; /* index in lgr link array */ u8 link_is_asym; /* is link asymmetric? */ u8 clearing : 1; /* link is being cleared */ + u8 rx_drained : 1; /* link is drained */ refcount_t refcnt; /* link reference count */ struct smc_link_group *lgr; /* parent link group */ struct work_struct link_down_wrk; /* wrk to bring link down */ diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c index 26f8f240d..3f782837b 100644 --- a/net/smc/smc_wr.c +++ b/net/smc/smc_wr.c @@ -465,6 +465,10 @@ static inline void smc_wr_rx_process_cqes(struct ib_wc wc[], int num) case IB_WC_RNR_RETRY_EXC_ERR: case IB_WC_WR_FLUSH_ERR: smcr_link_down_cond_sched(link); + if (link->clearing && wc[i].wr_id == link->wr_rx_id) { + link->rx_drained = 1; + wake_up(&link->wr_rx_drain_wait); + } break; default: smc_wr_rx_post(link); /* refill WR RX */ @@ -631,6 +635,13 @@ static void smc_wr_init_sge(struct smc_link *lnk) lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE; } +void smc_wr_drain_cq(struct smc_link *lnk) +{ + wait_event_interruptible_timeout(lnk->wr_rx_drain_wait, + (lnk->rx_drained == 1), + SMC_WR_RX_WAIT_DRAIN_TIME); +} + void smc_wr_free_link(struct smc_link *lnk) { struct ib_device *ibdev; @@ -889,6 +900,7 @@ int smc_wr_create_link(struct smc_link *lnk) atomic_set(&lnk->wr_tx_refcnt, 0); init_waitqueue_head(&lnk->wr_reg_wait); atomic_set(&lnk->wr_reg_refcnt, 0); + init_waitqueue_head(&lnk->wr_rx_drain_wait); return rc; dma_unmap: diff --git a/net/smc/smc_wr.h b/net/smc/smc_wr.h index a54e90a11..2a7ebdba3 100644 --- a/net/smc/smc_wr.h +++ b/net/smc/smc_wr.h @@ -27,6 +27,8 @@ #define SMC_WR_TX_PEND_PRIV_SIZE 32 +#define SMC_WR_RX_WAIT_DRAIN_TIME (2 * HZ) + struct smc_wr_tx_pend_priv { u8 priv[SMC_WR_TX_PEND_PRIV_SIZE]; }; @@ -101,6 +103,7 @@ static inline int smc_wr_rx_post(struct smc_link *link) int smc_wr_create_link(struct smc_link *lnk); int smc_wr_alloc_link_mem(struct smc_link *lnk); int smc_wr_alloc_lgr_mem(struct smc_link_group *lgr); +void smc_wr_drain_cq(struct smc_link *lnk); void smc_wr_free_link(struct smc_link *lnk); void smc_wr_free_link_mem(struct smc_link *lnk); void smc_wr_free_lgr_mem(struct smc_link_group *lgr);