Re: 3.12-rc3 memory leak in module memstick

[Larry Finger]

On 10/01/2013 09:04 AM, Catalin Marinas wrote:
> On 30 September 2013 18:51, Larry Finger <Larry.Finger@xxxxxxxxxxxx> 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.

Thanks for the analysis. From that I am quite sure I can devise a patch.

Larry


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