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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Changhui Zhong <czhong@redhat.com>,
	Yi Zhang <yi.zhang@redhat.com>, Ming Lei <ming.lei@redhat.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: [PATCH 4.14 01/22] scsi: core: Put LLD module refcnt after SCSI device is released
Date: Wed, 10 Nov 2021 19:43:21 +0100	[thread overview]
Message-ID: <20211110182002.714805076@linuxfoundation.org> (raw)
In-Reply-To: <20211110182002.666244094@linuxfoundation.org>

From: Ming Lei <ming.lei@redhat.com>

commit f2b85040acec9a928b4eb1b57a989324e8e38d3f upstream.

SCSI host release is triggered when SCSI device is freed. We have to make
sure that the low-level device driver module won't be unloaded before SCSI
host instance is released because shost->hostt is required in the release
handler.

Make sure to put LLD module refcnt after SCSI device is released.

Fixes a kernel panic of 'BUG: unable to handle page fault for address'
reported by Changhui and Yi.

Link: https://lore.kernel.org/r/20211008050118.1440686-1-ming.lei@redhat.com
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Changhui Zhong <czhong@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/scsi/scsi.c       |    4 +++-
 drivers/scsi/scsi_sysfs.c |    9 +++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -575,8 +575,10 @@ EXPORT_SYMBOL(scsi_device_get);
  */
 void scsi_device_put(struct scsi_device *sdev)
 {
-	module_put(sdev->host->hostt->module);
+	struct module *mod = sdev->host->hostt->module;
+
 	put_device(&sdev->sdev_gendev);
+	module_put(mod);
 }
 EXPORT_SYMBOL(scsi_device_put);
 
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -430,9 +430,12 @@ static void scsi_device_dev_release_user
 	struct list_head *this, *tmp;
 	struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
 	unsigned long flags;
+	struct module *mod;
 
 	sdev = container_of(work, struct scsi_device, ew.work);
 
+	mod = sdev->host->hostt->module;
+
 	scsi_dh_release_device(sdev);
 
 	parent = sdev->sdev_gendev.parent;
@@ -473,11 +476,17 @@ static void scsi_device_dev_release_user
 
 	if (parent)
 		put_device(parent);
+	module_put(mod);
 }
 
 static void scsi_device_dev_release(struct device *dev)
 {
 	struct scsi_device *sdp = to_scsi_device(dev);
+
+	/* Set module pointer as NULL in case of module unloading */
+	if (!try_module_get(sdp->host->hostt->module))
+		sdp->host->hostt->module = NULL;
+
 	execute_in_process_context(scsi_device_dev_release_usercontext,
 				   &sdp->ew);
 }



  reply	other threads:[~2021-11-10 18:46 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-10 18:43 [PATCH 4.14 00/22] 4.14.255-rc1 review Greg Kroah-Hartman
2021-11-10 18:43 ` Greg Kroah-Hartman [this message]
2021-11-10 18:43 ` [PATCH 4.14 02/22] media: firewire: firedtv-avc: fix a buffer overflow in avc_ca_pmt() Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 03/22] mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 04/22] arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 05/22] ARM: 9120/1: Revert "amba: make use of -1 IRQs warn" Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 06/22] IB/qib: Use struct_size() helper Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 07/22] IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 08/22] block: introduce multi-page bvec helpers Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 09/22] Revert "x86/kvm: fix vcpu-id indexed array sizes" Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 10/22] usb: gadget: Mark USB_FSL_QE broken on 64-bit Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 11/22] usb: musb: Balance list entry in musb_gadget_queue Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 12/22] usb-storage: Add compatibility quirk flags for iODD 2531/2541 Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 13/22] printk/console: Allow to disable console output by using console="" or console=null Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 14/22] isofs: Fix out of bound access for corrupted isofs image Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 15/22] comedi: dt9812: fix DMA buffers on stack Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 16/22] comedi: ni_usb6501: fix NULL-deref in command paths Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 17/22] comedi: vmk80xx: fix transfer-buffer overflows Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 18/22] comedi: vmk80xx: fix bulk-buffer overflow Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 19/22] comedi: vmk80xx: fix bulk and interrupt message timeouts Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 20/22] staging: r8712u: fix control-message timeout Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 21/22] staging: rtl8192u: fix control-message timeouts Greg Kroah-Hartman
2021-11-10 18:43 ` [PATCH 4.14 22/22] rsi: fix control-message timeout Greg Kroah-Hartman
2021-11-11 18:26 ` [PATCH 4.14 00/22] 4.14.255-rc1 review Naresh Kamboju
2021-11-12  0:58 ` Guenter Roeck
2021-11-12 15:41 ` Jon Hunter

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