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From: Catalin Marinas <catalin.marinas@arm.com>
Date: Tue, 1 Oct 2013 15:04:48 +0100
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Subject: Re: 3.12-rc3 memory leak in module memstick
To: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Alex Dubov <oakad@yahoo.com>, LKML <linux-kernel@vger.kernel.org>
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On 30 September 2013 18:51, Larry Finger <Larry.Finger@lwfinger.net> wrote:
> On 3.12-rc3, I detected a memory leak in module memstick. The kmemleak
> results are listed below. The second output is after memstick was unloaded,
> which shows that it is not a false positive from kmemleak.
>
> larrylap:~ # echo scan > /sys/kernel/debug/kmemleak
> larrylap:~ # cat /sys/kernel/debug/kmemleak
> unreferenced object 0xffff8800ae85c190 (size 16):
>   comm "kworker/u4:3", pid 685, jiffies 4294916336 (age 2831.760s)
>   hex dump (first 16 bytes):
>     6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00  memstick0.......
>   backtrace:
>     [<ffffffff8146a0d1>] kmemleak_alloc+0x21/0x50
>     [<ffffffff81160720>] __kmalloc_track_caller+0x160/0x2f0
>     [<ffffffff81237b9b>] kvasprintf+0x5b/0x90
>     [<ffffffff8122c0c1>] kobject_set_name_vargs+0x21/0x60
>     [<ffffffff812e7f5c>] dev_set_name+0x3c/0x40
>     [<ffffffffa02bf918>] memstick_check+0xb8/0x340 [memstick]
>     [<ffffffff81069862>] process_one_work+0x1d2/0x670
>     [<ffffffff8106a88a>] worker_thread+0x11a/0x370
>     [<ffffffff81072ea6>] kthread+0xd6/0xe0
>     [<ffffffff81478bbc>] ret_from_fork+0x7c/0xb0

The leak is most likely coming from memstick_alloc_card() on the error
path. Commit 0252c3b4f0 (memstick: struct device - replace bus_id with
dev_name(), dev_set_name()) sets allocates the device name but 'card'
is freed on the error path without freeing the name.

-- 
Catalin
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