[akpm-mm:mm-unstable 284/293] mm/khugepaged.c:2409 madvise_collapse() warn: possible memory leak of 'cc'

From: Dan Carpenter
Date: Tue Jul 12 2022 - 08:36:23 EST


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@xxxxxxxxx/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@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

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;

kfree(cc);?


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