mm/khugepaged: Avoid possible memory leak in failure path

smatch warnings:
mm/khugepaged.c:2409 madvise_collapse() warn: possible memory
leak of 'cc'

Avoiding possible memory leak.

Link: https://lkml.kernel.org/r/20220713024109.62810-1-jrdr.linux@gmail.com
Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 76e450cf2465e85200958734c530cac2d66dcf9d..3c8aa2db22be8a08db18db912d95df95cb055cec 100644 (file)
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2410,12 +2410,6 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
        BUG_ON(vma->vm_start > start);
        BUG_ON(vma->vm_end < end);
 
-       cc = kmalloc(sizeof(*cc), GFP_KERNEL);
-       if (!cc)
-               return -ENOMEM;
-       cc->is_khugepaged = false;
-       cc->last_target_node = NUMA_NO_NODE;
-
        *prev = vma;
 
        /* TODO: Support file/shmem */
@@ -2428,6 +2422,12 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
        if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false))
                return -EINVAL;
 
+       cc = kmalloc(sizeof(*cc), GFP_KERNEL);
+       if (!cc)
+               return -ENOMEM;
+       cc->is_khugepaged = false;
+       cc->last_target_node = NUMA_NO_NODE;
+
        mmgrab(mm);
        lru_add_drain_all();