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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Chuck Lever <chuck.lever@oracle.com>,
	Anna Schumaker <Anna.Schumaker@Netapp.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-nfs@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.7 30/53] xprtrdma: Prevent dereferencing r_xprt->rx_ep after it is freed
Date: Wed,  1 Jul 2020 21:21:39 -0400	[thread overview]
Message-ID: <20200702012202.2700645-30-sashal@kernel.org> (raw)
In-Reply-To: <20200702012202.2700645-1-sashal@kernel.org>

From: Chuck Lever <chuck.lever@oracle.com>

[ Upstream commit 2acc5cae292355f5f18ad377a2a966e7f03c8fec ]

r_xprt->rx_ep is known to be good while the transport's send lock is
held.  Otherwise additional references on rx_ep must be held when it
is used outside of that lock's critical sections.

For now, bump the rx_ep reference count once whenever there is at
least one outstanding Receive WR. This avoids the memory bandwidth
overhead of taking and releasing the reference count for every
ib_post_recv() and Receive completion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/sunrpc/xprtrdma/verbs.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 05c4d3a9cda27..db0259c6467ef 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -84,7 +84,8 @@ static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep);
 static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt);
 static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
 static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt);
-static int rpcrdma_ep_destroy(struct rpcrdma_ep *ep);
+static void rpcrdma_ep_get(struct rpcrdma_ep *ep);
+static int rpcrdma_ep_put(struct rpcrdma_ep *ep);
 static struct rpcrdma_regbuf *
 rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction,
 		     gfp_t flags);
@@ -97,7 +98,8 @@ static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb);
  */
 static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
 {
-	struct rdma_cm_id *id = r_xprt->rx_ep->re_id;
+	struct rpcrdma_ep *ep = r_xprt->rx_ep;
+	struct rdma_cm_id *id = ep->re_id;
 
 	/* Flush Receives, then wait for deferred Reply work
 	 * to complete.
@@ -108,6 +110,8 @@ static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
 	 * local invalidations.
 	 */
 	ib_drain_sq(id->qp);
+
+	rpcrdma_ep_put(ep);
 }
 
 /**
@@ -267,7 +271,7 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
 		xprt_force_disconnect(xprt);
 		goto disconnected;
 	case RDMA_CM_EVENT_ESTABLISHED:
-		kref_get(&ep->re_kref);
+		rpcrdma_ep_get(ep);
 		ep->re_connect_status = 1;
 		rpcrdma_update_cm_private(ep, &event->param.conn);
 		trace_xprtrdma_inline_thresh(ep);
@@ -290,7 +294,7 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
 		ep->re_connect_status = -ECONNABORTED;
 disconnected:
 		xprt_force_disconnect(xprt);
-		return rpcrdma_ep_destroy(ep);
+		return rpcrdma_ep_put(ep);
 	default:
 		break;
 	}
@@ -346,7 +350,7 @@ static struct rdma_cm_id *rpcrdma_create_id(struct rpcrdma_xprt *r_xprt,
 	return ERR_PTR(rc);
 }
 
-static void rpcrdma_ep_put(struct kref *kref)
+static void rpcrdma_ep_destroy(struct kref *kref)
 {
 	struct rpcrdma_ep *ep = container_of(kref, struct rpcrdma_ep, re_kref);
 
@@ -370,13 +374,18 @@ static void rpcrdma_ep_put(struct kref *kref)
 	module_put(THIS_MODULE);
 }
 
+static noinline void rpcrdma_ep_get(struct rpcrdma_ep *ep)
+{
+	kref_get(&ep->re_kref);
+}
+
 /* Returns:
  *     %0 if @ep still has a positive kref count, or
  *     %1 if @ep was destroyed successfully.
  */
-static int rpcrdma_ep_destroy(struct rpcrdma_ep *ep)
+static noinline int rpcrdma_ep_put(struct rpcrdma_ep *ep)
 {
-	return kref_put(&ep->re_kref, rpcrdma_ep_put);
+	return kref_put(&ep->re_kref, rpcrdma_ep_destroy);
 }
 
 static int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
@@ -493,7 +502,7 @@ static int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
 	return 0;
 
 out_destroy:
-	rpcrdma_ep_destroy(ep);
+	rpcrdma_ep_put(ep);
 	rdma_destroy_id(id);
 out_free:
 	kfree(ep);
@@ -522,8 +531,12 @@ int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt)
 
 	ep->re_connect_status = 0;
 	xprt_clear_connected(xprt);
-
 	rpcrdma_reset_cwnd(r_xprt);
+
+	/* Bump the ep's reference count while there are
+	 * outstanding Receives.
+	 */
+	rpcrdma_ep_get(ep);
 	rpcrdma_post_recvs(r_xprt, true);
 
 	rc = rpcrdma_sendctxs_create(r_xprt);
@@ -588,7 +601,7 @@ void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt)
 	rpcrdma_mrs_destroy(r_xprt);
 	rpcrdma_sendctxs_destroy(r_xprt);
 
-	if (rpcrdma_ep_destroy(ep))
+	if (rpcrdma_ep_put(ep))
 		rdma_destroy_id(id);
 
 	r_xprt->rx_ep = NULL;
-- 
2.25.1


  parent reply	other threads:[~2020-07-02  1:35 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-02  1:21 [PATCH AUTOSEL 5.7 01/53] soc: ti: omap-prm: use atomic iopoll instead of sleeping one Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 02/53] regmap: fix alignment issue Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 03/53] perf/x86/rapl: Move RAPL support to common x86 code Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 04/53] perf/x86/rapl: Fix RAPL config variable bug Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 05/53] ARM: dts: omap4-droid4: Fix spi configuration and increase rate Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 06/53] drm/ttm: Fix dma_fence refcnt leak in ttm_bo_vm_fault_reserved Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 07/53] drm/ttm: Fix dma_fence refcnt leak when adding move fence Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 08/53] gpu: host1x: Clean up debugfs in error handling path Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 09/53] drm/tegra: hub: Do not enable orphaned window group Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 10/53] gpu: host1x: Detach driver on unregister Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 11/53] btrfs: use kfree() in btrfs_ioctl_get_subvol_info() Sasha Levin
2020-07-02  8:25   ` David Sterba
2020-07-09 22:28     ` Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 12/53] staging: wfx: fix coherency of hif_scan() prototype Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 13/53] drm: mcde: Fix display initialization problem Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 14/53] ASoC: SOF: Intel: add PCI ID for CometLake-S Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 15/53] ASoC: SOF: Intel: add PCI IDs for ICL-H and TGL-H Sasha Levin
2020-07-02 11:18   ` Mark Brown
2020-07-02 15:42     ` Pierre-Louis Bossart
2020-07-02 16:05       ` Mark Brown
2020-07-09 22:29         ` Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 16/53] ASoC: hdac_hda: fix memleak with regmap not freed on remove Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 17/53] net: usb: ax88179_178a: fix packet alignment padding Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 18/53] ALSA: hda: Intel: add missing PCI IDs for ICL-H, TGL-H and EKL Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 19/53] usb: usbtest: fix missing kfree(dev->buf) in usbtest_disconnect Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 20/53] spi: spidev: fix a race between spidev_release and spidev_remove Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 21/53] spi: spidev: fix a potential use-after-free in spidev_release() Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 22/53] net: ethernet: mvneta: Fix Serdes configuration for SoCs without comphy Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 23/53] net: ethernet: mvneta: Add 2500BaseX support " Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 24/53] tg3: driver sleeps indefinitely when EEH errors exceed eeh_max_freezes Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 25/53] ixgbe: protect ring accesses with READ- and WRITE_ONCE Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 26/53] i40e: " Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 27/53] ice: protect ring accesses with WRITE_ONCE Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 28/53] ibmvnic: continue to init in CRQ reset returns H_CLOSED Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 29/53] powerpc/kvm/book3s64: Fix kernel crash with nested kvm & DEBUG_VIRTUAL Sasha Levin
2020-07-02  1:21 ` Sasha Levin [this message]
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 31/53] usbnet: smsc95xx: Fix use-after-free after removal Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 32/53] iommu/vt-d: Don't apply gfx quirks to untrusted devices Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 33/53] drm: panel-orientation-quirks: Add quirk for Asus T101HA panel Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 34/53] drm: panel-orientation-quirks: Use generic orientation-data for Acer S1003 Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 35/53] s390/kasan: fix early pgm check handler execution Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 36/53] s390/debug: avoid kernel warning on too large number of pages Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 37/53] cifs: Fix double add page to memcg when cifs_readpages Sasha Levin
2020-07-02 16:08   ` Pavel Shilovsky
2020-07-09 23:49     ` Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 38/53] drm/sun4i: mixer: Call of_dma_configure if there's an IOMMU Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 39/53] io_uring: fix io_sq_thread no schedule when busy Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 40/53] cifs: update ctime and mtime during truncate Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 41/53] ARM: imx6: add missing put_device() call in imx6q_suspend_init() Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 42/53] scsi: qla2xxx: Fix MPI failure AEN (8200) handling Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 43/53] scsi: mptscsih: Fix read sense data size Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 44/53] usb: dwc3: pci: Fix reference count leak in dwc3_pci_resume_work Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 45/53] arm64: kpti: Add KRYO{3, 4}XX silver CPU cores to kpti safelist Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 46/53] block: release bip in a right way in error path Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 47/53] nvme-rdma: assign completion vector correctly Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 48/53] x86/entry: Increase entry_stack size to a full page Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 49/53] io_uring: fix current->mm NULL dereference on exit Sasha Levin
2020-07-02  1:21 ` [PATCH AUTOSEL 5.7 50/53] arm64: Add KRYO{3,4}XX silver CPU cores to SSB safelist Sasha Levin
2020-07-02  1:22 ` [PATCH AUTOSEL 5.7 51/53] nfs: Fix memory leak of export_path Sasha Levin
2020-07-02  1:22 ` [PATCH AUTOSEL 5.7 52/53] kgdb: Avoid suspicious RCU usage warning Sasha Levin
2020-07-02  1:22 ` [PATCH AUTOSEL 5.7 53/53] sched/core: Check cpus_mask, not cpus_ptr in __set_cpus_allowed_ptr(), to fix mask corruption Sasha Levin

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