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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, zhengbin <zhengbin13@huawei.com>,
	Jens Axboe <axboe@kernel.dk>,
	Jack Wang <jinpu.wang@cloud.ionos.com>
Subject: [PATCH 4.19 02/24] block: fix NULL pointer dereference in register_disk
Date: Thu, 11 Feb 2021 16:02:36 +0100
Message-ID: <20210211150147.866158359@linuxfoundation.org> (raw)
In-Reply-To: <20210211150147.743660073@linuxfoundation.org>

From: zhengbin <zhengbin13@huawei.com>

commit 4d7c1d3fd7c7eda7dea351f071945e843a46c145 upstream.

If __device_add_disk-->bdi_register_owner-->bdi_register-->
bdi_register_va-->device_create_vargs fails, bdi->dev is still
NULL, __device_add_disk-->register_disk will visit bdi->dev->kobj.
This patch fixes that.

Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
 block/genhd.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/block/genhd.c
+++ b/block/genhd.c
@@ -652,10 +652,12 @@ exit:
 		kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
 	disk_part_iter_exit(&piter);
 
-	err = sysfs_create_link(&ddev->kobj,
-				&disk->queue->backing_dev_info->dev->kobj,
-				"bdi");
-	WARN_ON(err);
+	if (disk->queue->backing_dev_info->dev) {
+		err = sysfs_create_link(&ddev->kobj,
+			  &disk->queue->backing_dev_info->dev->kobj,
+			  "bdi");
+		WARN_ON(err);
+	}
 }
 
 /**



  parent reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-11 15:02 [PATCH 4.19 00/24] 4.19.176-rc1 review Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 01/24] tracing/kprobe: Fix to support kretprobe events on unloaded modules Greg Kroah-Hartman
2021-02-11 15:02 ` Greg Kroah-Hartman [this message]
2021-02-11 15:02 ` [PATCH 4.19 03/24] fgraph: Initialize tracing_graph_pause at task creation Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 04/24] remoteproc: qcom_q6v5_mss: Validate modem blob firmware size before load Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 05/24] remoteproc: qcom_q6v5_mss: Validate MBA " Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 06/24] af_key: relax availability checks for skb size calculation Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 07/24] regulator: core: avoid regulator_resolve_supply() race condition Greg Kroah-Hartman
2021-02-11 15:26   ` Mark Brown
2021-02-11 15:38     ` Greg Kroah-Hartman
2021-02-11 15:40       ` Mark Brown
2021-02-11 18:06         ` Sasha Levin
2021-02-11 15:02 ` [PATCH 4.19 08/24] chtls: Fix potential resource leak Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 09/24] pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process() Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 10/24] iwlwifi: mvm: take mutex for calling iwl_mvm_get_sync_time() Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 11/24] iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 12/24] iwlwifi: pcie: fix context info memory leak Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 13/24] iwlwifi: mvm: guard against device removal in reprobe Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 14/24] SUNRPC: Move simple_get_bytes and simple_get_netobj into private header Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 15/24] SUNRPC: Handle 0 length opaque XDR object data properly Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 16/24] lib/string: Add strscpy_pad() function Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 17/24] include/trace/events/writeback.h: fix -Wstringop-truncation warnings Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 18/24] memcg: fix a crash in wb_workfn when a device disappears Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 19/24] Fix unsynchronized access to sev members through svm_register_enc_region Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 20/24] block: dont hold q->sysfs_lock in elevator_init_mq Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 21/24] blk-mq: dont hold q->sysfs_lock in blk_mq_map_swqueue Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 22/24] squashfs: add more sanity checks in id lookup Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 23/24] squashfs: add more sanity checks in inode lookup Greg Kroah-Hartman
2021-02-11 15:02 ` [PATCH 4.19 24/24] squashfs: add more sanity checks in xattr id lookup Greg Kroah-Hartman
2021-02-12  4:46 ` [PATCH 4.19 00/24] 4.19.176-rc1 review Naresh Kamboju
2021-02-12  7:42   ` Greg Kroah-Hartman
2021-02-12 10:29     ` Naresh Kamboju
2021-02-12 11:00       ` Greg Kroah-Hartman
2021-02-12 16:18 ` Shuah Khan

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