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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2017-11-29 16:11:30 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-29 18:40:43 -0800 |
| commit | f4f0a3d85b50a65a348e2b8635041d6b30f01deb (patch) | |
| tree | 11b100039752f93f1ca110a7c8f02cae39448f7a /fs/jbd2/checkpoint.c | |
| parent | 5d38f049cee1e1c4a7ac55aa79d37d01ddcc3860 (diff) | |
| download | linux-f4f0a3d85b50a65a348e2b8635041d6b30f01deb.tar.bz2 | |
mm/hugetlb: fix NULL-pointer dereference on 5-level paging machine
I made a mistake during converting hugetlb code to 5-level paging: in
huge_pte_alloc() we have to use p4d_alloc(), not p4d_offset().
Otherwise it leads to crash -- NULL-pointer dereference in pud_alloc()
if p4d table is not yet allocated.
It only can happen in 5-level paging mode. In 4-level paging mode
p4d_offset() always returns pgd, so we are fine.
Link: http://lkml.kernel.org/r/20171122121921.64822-1-kirill.shutemov@linux.intel.com
Fixes: c2febafc6773 ("mm: convert generic code to 5-level paging")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/jbd2/checkpoint.c')
0 files changed, 0 insertions, 0 deletions