2022-07-12 12:53:35

by Dan Carpenter

[permalink] [raw]
Subject: [ammarfaizi2-block:shuah/linux-kselftest/kunit 4/16] lib/kunit/executor.c:78 kunit_filter_tests() warn: possible memory leak of 'copy'

tree: https://github.com/ammarfaizi2/linux-block shuah/linux-kselftest/kunit
head: 7635778bac7e46458392c1261e3916e8e9e86860
commit: d2fbdde838f270377de4fc20e919aac3941ea55f [4/16] kunit: use kmemdup in kunit_filter_tests(), take suite as const
config: arc-randconfig-m031-20220707 (https://download.01.org/0day-ci/archive/20220710/[email protected]/config)
compiler: arc-elf-gcc (GCC) 11.3.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>

smatch warnings:
lib/kunit/executor.c:78 kunit_filter_tests() warn: possible memory leak of 'copy'

vim +/copy +78 lib/kunit/executor.c

a127b154a8f2317 Daniel Latypov 2021-09-14 57 static struct kunit_suite *
d2fbdde838f2703 Daniel Latypov 2022-05-16 58 kunit_filter_tests(const struct kunit_suite *const suite, const char *test_glob)
a127b154a8f2317 Daniel Latypov 2021-09-14 59 {
a127b154a8f2317 Daniel Latypov 2021-09-14 60 int n = 0;
a127b154a8f2317 Daniel Latypov 2021-09-14 61 struct kunit_case *filtered, *test_case;
a127b154a8f2317 Daniel Latypov 2021-09-14 62 struct kunit_suite *copy;
a127b154a8f2317 Daniel Latypov 2021-09-14 63
a127b154a8f2317 Daniel Latypov 2021-09-14 64 kunit_suite_for_each_test_case(suite, test_case) {
a127b154a8f2317 Daniel Latypov 2021-09-14 65 if (!test_glob || glob_match(test_glob, test_case->name))
a127b154a8f2317 Daniel Latypov 2021-09-14 66 ++n;
a127b154a8f2317 Daniel Latypov 2021-09-14 67 }
a127b154a8f2317 Daniel Latypov 2021-09-14 68
a127b154a8f2317 Daniel Latypov 2021-09-14 69 if (n == 0)
a127b154a8f2317 Daniel Latypov 2021-09-14 70 return NULL;
a127b154a8f2317 Daniel Latypov 2021-09-14 71
d2fbdde838f2703 Daniel Latypov 2022-05-16 72 copy = kmemdup(suite, sizeof(*copy), GFP_KERNEL);
a02353f491622e4 Daniel Latypov 2022-05-11 73 if (!copy)
a02353f491622e4 Daniel Latypov 2022-05-11 74 return ERR_PTR(-ENOMEM);
a127b154a8f2317 Daniel Latypov 2021-09-14 75
a127b154a8f2317 Daniel Latypov 2021-09-14 76 filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
a02353f491622e4 Daniel Latypov 2022-05-11 77 if (!filtered)
a02353f491622e4 Daniel Latypov 2022-05-11 @78 return ERR_PTR(-ENOMEM);

kfree(copy)? Is the burden of random devs looking at this warning
forever more than the burden of adding a kfree()? Hard to measure.

a127b154a8f2317 Daniel Latypov 2021-09-14 79
a127b154a8f2317 Daniel Latypov 2021-09-14 80 n = 0;
a127b154a8f2317 Daniel Latypov 2021-09-14 81 kunit_suite_for_each_test_case(suite, test_case) {
a127b154a8f2317 Daniel Latypov 2021-09-14 82 if (!test_glob || glob_match(test_glob, test_case->name))
a127b154a8f2317 Daniel Latypov 2021-09-14 83 filtered[n++] = *test_case;
a127b154a8f2317 Daniel Latypov 2021-09-14 84 }
a127b154a8f2317 Daniel Latypov 2021-09-14 85
a127b154a8f2317 Daniel Latypov 2021-09-14 86 copy->test_cases = filtered;
a127b154a8f2317 Daniel Latypov 2021-09-14 87 return copy;
a127b154a8f2317 Daniel Latypov 2021-09-14 88 }

--
0-DAY CI Kernel Test Service
https://01.org/lkp


2022-07-12 13:59:48

by David Gow

[permalink] [raw]
Subject: Re: [ammarfaizi2-block:shuah/linux-kselftest/kunit 4/16] lib/kunit/executor.c:78 kunit_filter_tests() warn: possible memory leak of 'copy'

On Tue, Jul 12, 2022 at 8:51 PM Dan Carpenter <[email protected]> wrote:
>
> tree: https://github.com/ammarfaizi2/linux-block shuah/linux-kselftest/kunit
> head: 7635778bac7e46458392c1261e3916e8e9e86860
> commit: d2fbdde838f270377de4fc20e919aac3941ea55f [4/16] kunit: use kmemdup in kunit_filter_tests(), take suite as const
> config: arc-randconfig-m031-20220707 (https://download.01.org/0day-ci/archive/20220710/[email protected]/config)
> compiler: arc-elf-gcc (GCC) 11.3.0
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
>
> smatch warnings:
> lib/kunit/executor.c:78 kunit_filter_tests() warn: possible memory leak of 'copy'
>
> vim +/copy +78 lib/kunit/executor.c

Thanks: clang-analyzer also picked this up here:
https://lore.kernel.org/all/[email protected]/

(... snip ...)

> a127b154a8f2317 Daniel Latypov 2021-09-14 76 filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
> a02353f491622e4 Daniel Latypov 2022-05-11 77 if (!filtered)
> a02353f491622e4 Daniel Latypov 2022-05-11 @78 return ERR_PTR(-ENOMEM);
>
> kfree(copy)? Is the burden of random devs looking at this warning
> forever more than the burden of adding a kfree()? Hard to measure.
>

I mean, it's the burden of not only adding a kfree(), but also a
couple of {}s. :-)

Regardless, this patch should add them:
https://lore.kernel.org/linux-kselftest/[email protected]/

> a127b154a8f2317 Daniel Latypov 2021-09-14 79
> a127b154a8f2317 Daniel Latypov 2021-09-14 80 n = 0;
> a127b154a8f2317 Daniel Latypov 2021-09-14 81 kunit_suite_for_each_test_case(suite, test_case) {
> a127b154a8f2317 Daniel Latypov 2021-09-14 82 if (!test_glob || glob_match(test_glob, test_case->name))
> a127b154a8f2317 Daniel Latypov 2021-09-14 83 filtered[n++] = *test_case;
> a127b154a8f2317 Daniel Latypov 2021-09-14 84 }
> a127b154a8f2317 Daniel Latypov 2021-09-14 85
> a127b154a8f2317 Daniel Latypov 2021-09-14 86 copy->test_cases = filtered;
> a127b154a8f2317 Daniel Latypov 2021-09-14 87 return copy;
> a127b154a8f2317 Daniel Latypov 2021-09-14 88 }
>

Cheers,
-- David