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From: Gioh Kim <gi-oh.kim@ionos.com>
To: linux-block@vger.kernel.org, linux-doc@vger.kernel.org
Cc: axboe@kernel.dk, akinobu.mita@gmail.com, corbet@lwn.net,
	hch@infradead.org, sagi@grimberg.me, bvanassche@acm.org,
	haris.iqbal@ionos.com, jinpu.wang@ionos.com,
	Gioh Kim <gi-oh.kim@cloud.ionos.com>,
	Gioh Kim <gi-oh.kim@ionos.com>
Subject: [PATCHv5 for-next 12/19] block/rnbd-clt: Fix missing a memory free when unloading the module
Date: Mon, 19 Apr 2021 09:37:15 +0200
Message-ID: <20210419073722.15351-13-gi-oh.kim@ionos.com> (raw)
In-Reply-To: <20210419073722.15351-1-gi-oh.kim@ionos.com>

From: Gioh Kim <gi-oh.kim@cloud.ionos.com>

When unloading the rnbd-clt module, it does not free a memory
including the filename of the symbolic link to /sys/block/rnbdX.

It is found by kmemleak as below.

unreferenced object 0xffff9f1a83d3c740 (size 16):
  comm "bash", pid 736, jiffies 4295179665 (age 9841.310s)
  hex dump (first 16 bytes):
    21 64 65 76 21 6e 75 6c 6c 62 30 40 62 6c 61 00  !dev!nullb0@bla.
  backtrace:
    [<0000000039f0c55e>] 0xffffffffc0456c24
    [<000000001aab9513>] kernfs_fop_write+0xcf/0x1c0
    [<00000000db5aa4b3>] vfs_write+0xdb/0x1d0
    [<000000007a2e2207>] ksys_write+0x65/0xe0
    [<00000000055e280a>] do_syscall_64+0x50/0x1b0
    [<00000000c2b51831>] entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
---
 drivers/block/rnbd/rnbd-clt-sysfs.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c
index 58c2cc0725b6..49015f428e67 100644
--- a/drivers/block/rnbd/rnbd-clt-sysfs.c
+++ b/drivers/block/rnbd/rnbd-clt-sysfs.c
@@ -432,10 +432,14 @@ void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
 	 * i.e. rnbd_clt_unmap_dev_store() leading to a sysfs warning because
 	 * of sysfs link already was removed already.
 	 */
-	if (dev->blk_symlink_name && try_module_get(THIS_MODULE)) {
-		sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
+	if (dev->blk_symlink_name) {
+		if (try_module_get(THIS_MODULE)) {
+			sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
+			module_put(THIS_MODULE);
+		}
+		/* It should be freed always. */
 		kfree(dev->blk_symlink_name);
-		module_put(THIS_MODULE);
+		dev->blk_symlink_name = NULL;
 	}
 }
 
-- 
2.25.1


  parent reply index

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-19  7:37 [PATCHv5 for-next 00/19] Misc update for rnbd Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 01/19] MAINTAINERS: Change maintainer for rnbd module Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 02/19] Documentation/sysfs-block-rnbd: Add descriptions for remap_device and resize Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 03/19] block/rnbd-clt: Remove some arguments from insert_dev_if_not_exists_devpath Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 04/19] block/rnbd-clt: Remove some arguments from rnbd_client_setup_device Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 05/19] block/rnbd-clt: Move add_disk(dev->gd) to rnbd_clt_setup_gen_disk Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 06/19] block/rnbd: Kill rnbd_clt_destroy_default_group Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 07/19] block/rnbd: Kill destroy_device_cb Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 08/19] block/rnbd-clt: Replace {NO_WAIT,WAIT} with RTRS_PERMIT_{WAIT,NOWAIT} Gioh Kim
2021-04-19  7:46   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 09/19] block/rnbd-srv: Prevent a deadlock generated by accessing sysfs in parallel Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 10/19] block/rnbd-srv: Remove force_close file after holding a lock Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 11/19] block/rnbd-clt: Improve find_or_create_sess() return check Gioh Kim
2021-04-19  7:37 ` Gioh Kim [this message]
2021-04-19  7:37 ` [PATCHv5 for-next 13/19] block/rnbd-clt: Support polling mode for IO latency optimization Gioh Kim
2021-04-19  7:47   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 14/19] Documentation/ABI/rnbd-clt: Add description for nr_poll_queues Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 15/19] block/rnbd-srv: Remove unused arguments of rnbd_srv_rdma_ev Gioh Kim
2021-04-19  7:47   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 16/19] block/rnbd-clt: Generate kobject_uevent when the rnbd device state changes Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 17/19] block/rnbd-clt: Remove max_segment_size Gioh Kim
2021-04-19  7:47   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 18/19] block/rnbd-clt-sysfs: Remove copy buffer overlap in rnbd_clt_get_path_name Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 19/19] block/rnbd: Use strscpy instead of strlcpy Gioh Kim
2021-04-19 17:54 ` [PATCHv5 for-next 00/19] Misc update for rnbd Jens Axboe

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