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[95.90.238.229]) by smtp.googlemail.com with ESMTPSA id g22sm8701833ejz.46.2021.04.19.00.37.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Apr 2021 00:37:58 -0700 (PDT) From: Gioh Kim 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 , Gioh Kim 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> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210419073722.15351-1-gi-oh.kim@ionos.com> References: <20210419073722.15351-1-gi-oh.kim@ionos.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Gioh Kim 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 Signed-off-by: Jack Wang --- 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; } }