]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm, kasan: fix to call kasan_free_pages() after poisoning page
authorseokhoon.yoon <iamyooon@gmail.com>
Fri, 20 May 2016 23:58:47 +0000 (16:58 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 21 May 2016 00:58:30 +0000 (17:58 -0700)
commit29b52de182acf50f85a8284ad39104d84c9bbf57
tree79b8aa6e41e9107ef1c71eee4f0285d81fc0d80b
parentd0834a6c2c5b0c76cfb806bd7dba6556d8b4edbb
mm, kasan: fix to call kasan_free_pages() after poisoning page

When CONFIG_PAGE_POISONING and CONFIG_KASAN is enabled,
free_pages_prepare()'s codeflow is below.

  1)kmemcheck_free_shadow()
  2)kasan_free_pages()
    - set shadow byte of page is freed
  3)kernel_poison_pages()
  3.1) check access to page is valid or not using kasan
    ---> error occur, kasan think it is invalid access
  3.2) poison page
  4)kernel_map_pages()

So kasan_free_pages() should be called after poisoning the page.

Link: http://lkml.kernel.org/r/1463220405-7455-1-git-send-email-iamyooon@gmail.com
Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/page_alloc.c