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[PATCH] iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table()

Jinjie Ruan posted 1 patch 1 month, 2 weeks ago 
drivers/iio/industrialio-gts-helper.c | 2 ++
1 file changed, 2 insertions(+)
[PATCH] iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table()
Posted by Jinjie Ruan 1 month, 2 weeks ago 
modprobe iio-test-gts and rmmod it, then the following memory leak
occurs:

	unreferenced object 0xffffff80c810be00 (size 64):
	  comm "kunit_try_catch", pid 1654, jiffies 4294913981
	  hex dump (first 32 bytes):
	    02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00  ........ ...@...
	    80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00  ................
	  backtrace (crc a63d875e):
	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
	    [<0000000071bb4b09>] 0xffffffdf052a62e0
	    [<000000000315bc18>] 0xffffffdf052a6488
	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
	    [<00000000f505065d>] kthread+0x2e8/0x374
	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
	unreferenced object 0xffffff80cbfe9e70 (size 16):
	  comm "kunit_try_catch", pid 1658, jiffies 4294914015
	  hex dump (first 16 bytes):
	    10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00  ....@...........
	  backtrace (crc 857f0cb4):
	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
	    [<0000000071bb4b09>] 0xffffffdf052a62e0
	    [<000000007d089d45>] 0xffffffdf052a6864
	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
	    [<00000000f505065d>] kthread+0x2e8/0x374
	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
	......

It includes 5*5 times "size 64" memory leaks, which correspond to 5 times
test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int))
and gts_test_itimes size 5. It also includes 5*1 times "size 16"
memory leak, which correspond to one time __test_init_iio_gain_scale()
call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes
size 5.

The reason is that the per_time_gains[i] is not freed which is allocated in
the "gts->num_itime" for loop in iio_gts_build_avail_scale_table().

Cc: stable@vger.kernel.org
Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 drivers/iio/industrialio-gts-helper.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c
index 59d7615c0f56..7326c7949244 100644
--- a/drivers/iio/industrialio-gts-helper.c
+++ b/drivers/iio/industrialio-gts-helper.c
@@ -307,6 +307,8 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts)
 	if (ret)
 		goto err_free_out;
 
+	for (i = 0; i < gts->num_itime; i++)
+		kfree(per_time_gains[i]);
 	kfree(per_time_gains);
 	gts->per_time_avail_scale_tables = per_time_scales;
 
-- 
2.34.1
Re: [PATCH] iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table()
Posted by Jonathan Cameron 1 month, 2 weeks ago 
On Fri, 11 Oct 2024 17:55:12 +0800
Jinjie Ruan <ruanjinjie@huawei.com> wrote:

> modprobe iio-test-gts and rmmod it, then the following memory leak
> occurs:
> 
> 	unreferenced object 0xffffff80c810be00 (size 64):
> 	  comm "kunit_try_catch", pid 1654, jiffies 4294913981
> 	  hex dump (first 32 bytes):
> 	    02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00  ........ ...@...
> 	    80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00  ................
> 	  backtrace (crc a63d875e):
> 	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
> 	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
> 	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
> 	    [<0000000071bb4b09>] 0xffffffdf052a62e0
> 	    [<000000000315bc18>] 0xffffffdf052a6488
> 	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
> 	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
> 	    [<00000000f505065d>] kthread+0x2e8/0x374
> 	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
> 	unreferenced object 0xffffff80cbfe9e70 (size 16):
> 	  comm "kunit_try_catch", pid 1658, jiffies 4294914015
> 	  hex dump (first 16 bytes):
> 	    10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00  ....@...........
> 	  backtrace (crc 857f0cb4):
> 	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
> 	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
> 	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
> 	    [<0000000071bb4b09>] 0xffffffdf052a62e0
> 	    [<000000007d089d45>] 0xffffffdf052a6864
> 	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
> 	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
> 	    [<00000000f505065d>] kthread+0x2e8/0x374
> 	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
> 	......
> 
> It includes 5*5 times "size 64" memory leaks, which correspond to 5 times
> test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int))
> and gts_test_itimes size 5. It also includes 5*1 times "size 16"
> memory leak, which correspond to one time __test_init_iio_gain_scale()
> call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes
> size 5.
> 
> The reason is that the per_time_gains[i] is not freed which is allocated in
> the "gts->num_itime" for loop in iio_gts_build_avail_scale_table().
> 
> Cc: stable@vger.kernel.org
> Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Hi Jinjie,

Your explanation looks correct to me.  I'll wait a while though to give Matti time
to take a look as well.

Thanks,

Jonathan

> ---
>  drivers/iio/industrialio-gts-helper.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c
> index 59d7615c0f56..7326c7949244 100644
> --- a/drivers/iio/industrialio-gts-helper.c
> +++ b/drivers/iio/industrialio-gts-helper.c
> @@ -307,6 +307,8 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts)
>  	if (ret)
>  		goto err_free_out;
>  
> +	for (i = 0; i < gts->num_itime; i++)
> +		kfree(per_time_gains[i]);
>  	kfree(per_time_gains);
>  	gts->per_time_avail_scale_tables = per_time_scales;
>
Re: [PATCH] iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table()
Posted by Matti Vaittinen 1 month, 1 week ago 
Hi Jinjie, Jonathan,

On 12/10/2024 19:15, Jonathan Cameron wrote:
> On Fri, 11 Oct 2024 17:55:12 +0800
> Jinjie Ruan <ruanjinjie@huawei.com> wrote:
> 
>> modprobe iio-test-gts and rmmod it, then the following memory leak
>> occurs:
>>
>> 	unreferenced object 0xffffff80c810be00 (size 64):
>> 	  comm "kunit_try_catch", pid 1654, jiffies 4294913981
>> 	  hex dump (first 32 bytes):
>> 	    02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00  ........ ...@...
>> 	    80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00  ................
>> 	  backtrace (crc a63d875e):
>> 	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
>> 	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
>> 	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
>> 	    [<0000000071bb4b09>] 0xffffffdf052a62e0
>> 	    [<000000000315bc18>] 0xffffffdf052a6488
>> 	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
>> 	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
>> 	    [<00000000f505065d>] kthread+0x2e8/0x374
>> 	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
>> 	unreferenced object 0xffffff80cbfe9e70 (size 16):
>> 	  comm "kunit_try_catch", pid 1658, jiffies 4294914015
>> 	  hex dump (first 16 bytes):
>> 	    10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00  ....@...........
>> 	  backtrace (crc 857f0cb4):
>> 	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
>> 	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
>> 	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
>> 	    [<0000000071bb4b09>] 0xffffffdf052a62e0
>> 	    [<000000007d089d45>] 0xffffffdf052a6864
>> 	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
>> 	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
>> 	    [<00000000f505065d>] kthread+0x2e8/0x374
>> 	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
>> 	......
>>
>> It includes 5*5 times "size 64" memory leaks, which correspond to 5 times
>> test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int))
>> and gts_test_itimes size 5. It also includes 5*1 times "size 16"
>> memory leak, which correspond to one time __test_init_iio_gain_scale()
>> call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes
>> size 5.
>>
>> The reason is that the per_time_gains[i] is not freed which is allocated in
>> the "gts->num_itime" for loop in iio_gts_build_avail_scale_table().
>>
>> Cc: stable@vger.kernel.org
>> Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers")
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> Hi Jinjie,
> 
> Your explanation looks correct to me.  I'll wait a while though to give Matti time
> to take a look as well.

Sorry for late reply - I spent last couple of days walking through the 
swamps and forests in the wilderness.

Something was bothering me with this. I browsed through the code and all 
the allocations and I'm not able to see why these arrays shouldn't be 
freed. I did even go through the versions I've sent on list trying to 
find out what bothers me.

Well, I found nothing. The version 2 had some code which looped through 
these arrays freeing them - in an error path - but not in successful 
case. It seemed as if I had thought these values had to be maintained - 
but I really can't see why.

So - thanks. I suppose leaving the memory not freed is just a bug :) 
Nice that you killed this one :)

Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>

> 
> Thanks,
> 
> Jonathan
> 
>> ---
>>   drivers/iio/industrialio-gts-helper.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c
>> index 59d7615c0f56..7326c7949244 100644
>> --- a/drivers/iio/industrialio-gts-helper.c
>> +++ b/drivers/iio/industrialio-gts-helper.c
>> @@ -307,6 +307,8 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts)
>>   	if (ret)
>>   		goto err_free_out;
>>   
>> +	for (i = 0; i < gts->num_itime; i++)
>> +		kfree(per_time_gains[i]);
>>   	kfree(per_time_gains);
>>   	gts->per_time_avail_scale_tables = per_time_scales;
>>   
>
Re: [PATCH] iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table()
Posted by Jonathan Cameron 1 month, 1 week ago 
On Tue, 15 Oct 2024 09:26:54 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> Hi Jinjie, Jonathan,
> 
> On 12/10/2024 19:15, Jonathan Cameron wrote:
> > On Fri, 11 Oct 2024 17:55:12 +0800
> > Jinjie Ruan <ruanjinjie@huawei.com> wrote:
> >   
> >> modprobe iio-test-gts and rmmod it, then the following memory leak
> >> occurs:
> >>
> >> 	unreferenced object 0xffffff80c810be00 (size 64):
> >> 	  comm "kunit_try_catch", pid 1654, jiffies 4294913981
> >> 	  hex dump (first 32 bytes):
> >> 	    02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00  ........ ...@...
> >> 	    80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00  ................
> >> 	  backtrace (crc a63d875e):
> >> 	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
> >> 	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
> >> 	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
> >> 	    [<0000000071bb4b09>] 0xffffffdf052a62e0
> >> 	    [<000000000315bc18>] 0xffffffdf052a6488
> >> 	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
> >> 	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
> >> 	    [<00000000f505065d>] kthread+0x2e8/0x374
> >> 	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
> >> 	unreferenced object 0xffffff80cbfe9e70 (size 16):
> >> 	  comm "kunit_try_catch", pid 1658, jiffies 4294914015
> >> 	  hex dump (first 16 bytes):
> >> 	    10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00  ....@...........
> >> 	  backtrace (crc 857f0cb4):
> >> 	    [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40
> >> 	    [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0
> >> 	    [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4
> >> 	    [<0000000071bb4b09>] 0xffffffdf052a62e0
> >> 	    [<000000007d089d45>] 0xffffffdf052a6864
> >> 	    [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac
> >> 	    [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec
> >> 	    [<00000000f505065d>] kthread+0x2e8/0x374
> >> 	    [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20
> >> 	......
> >>
> >> It includes 5*5 times "size 64" memory leaks, which correspond to 5 times
> >> test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int))
> >> and gts_test_itimes size 5. It also includes 5*1 times "size 16"
> >> memory leak, which correspond to one time __test_init_iio_gain_scale()
> >> call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes
> >> size 5.
> >>
> >> The reason is that the per_time_gains[i] is not freed which is allocated in
> >> the "gts->num_itime" for loop in iio_gts_build_avail_scale_table().
> >>
> >> Cc: stable@vger.kernel.org
> >> Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers")
> >> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>  
> > Hi Jinjie,
> > 
> > Your explanation looks correct to me.  I'll wait a while though to give Matti time
> > to take a look as well.  
> 
> Sorry for late reply - I spent last couple of days walking through the 
> swamps and forests in the wilderness.
> 
> Something was bothering me with this. I browsed through the code and all 
> the allocations and I'm not able to see why these arrays shouldn't be 
> freed. I did even go through the versions I've sent on list trying to 
> find out what bothers me.
> 
> Well, I found nothing. The version 2 had some code which looped through 
> these arrays freeing them - in an error path - but not in successful 
> case. It seemed as if I had thought these values had to be maintained - 
> but I really can't see why.
> 
> So - thanks. I suppose leaving the memory not freed is just a bug :) 
> Nice that you killed this one :)
> 
> Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Applied to the fixes-togreg branch of iio.git.

Thanks,

Jonathan

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