From: Yang Shi <shy828301@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: kbuild@lists.01.org, "Zach O'Keefe" <zokeefe@google.com>,
kernel test robot <lkp@intel.com>,
kbuild-all@lists.01.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [akpm-mm:mm-unstable 284/293] mm/khugepaged.c:2409 madvise_collapse() warn: possible memory leak of 'cc'
Date: Tue, 12 Jul 2022 10:02:53 -0700 [thread overview]
Message-ID: <CAHbLzkoFjZoX0WFy9YaOO1rEC+=yyytgDimapeTEyuNyMNTHLg@mail.gmail.com> (raw)
In-Reply-To: <202207100715.TBIYQ4fc-lkp@intel.com>
On Tue, Jul 12, 2022 at 5:36 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable
> head: 0e9f775fb0b4adf1a4ef50ea156ead09a0fc5194
> commit: 9f626ffb1d1c5c26b4a8e0fdffec784a5f773274 [284/293] mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse
> config: i386-randconfig-m021 (https://download.01.org/0day-ci/archive/20220710/202207100715.TBIYQ4fc-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.3.0-3) 11.3.0
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> smatch warnings:
> mm/khugepaged.c:2409 madvise_collapse() warn: possible memory leak of 'cc'
>
> vim +/cc +2409 mm/khugepaged.c
>
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2387 int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2388 unsigned long start, unsigned long end)
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2389 {
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2390 struct collapse_control *cc;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2391 struct mm_struct *mm = vma->vm_mm;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2392 unsigned long hstart, hend, addr;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2393 int thps = 0, last_fail = SCAN_FAIL;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2394 bool mmap_locked = true;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2395
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2396 BUG_ON(vma->vm_start > start);
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2397 BUG_ON(vma->vm_end < end);
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2398
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2399 cc = kmalloc(sizeof(*cc), GFP_KERNEL);
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2400 if (!cc)
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2401 return -ENOMEM;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2402 cc->is_khugepaged = false;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2403 cc->last_target_node = NUMA_NO_NODE;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2404
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2405 *prev = vma;
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2406
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2407 /* TODO: Support file/shmem */
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2408 if (!vma->anon_vma || !vma_is_anonymous(vma))
> 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 @2409 return -EINVAL;
It seems better to move the cc kmalloc after the anonymous vma check?
>
> kfree(cc);?
>
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
>
>
next prev parent reply other threads:[~2022-07-12 17:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-12 12:35 Dan Carpenter
2022-07-12 13:46 ` Zach O'Keefe
2022-07-12 17:02 ` Yang Shi [this message]
2022-07-13 14:24 ` Zach O'Keefe
2022-07-13 19:04 ` Yang Shi
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