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| author | Shijie Luo <luoshijie1@huawei.com> | 2020-11-02 02:07:40 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-11-02 21:14:19 +0100 |
| commit | 3f08842098e842c51e3b97d0dcdebf810b32558e (patch) | |
| tree | a1b568a08112ffb7898d89e8bbf3d7fc36715bfd /kernel/signal.c | |
| parent | kasan: adopt KUNIT tests to SW_TAGS mode (diff) | |
| download | linux-3f08842098e842c51e3b97d0dcdebf810b32558e.tar.xz linux-3f08842098e842c51e3b97d0dcdebf810b32558e.zip | |
mm: mempolicy: fix potential pte_unmap_unlock pte error
When flags in queue_pages_pte_range don't have MPOL_MF_MOVE or
MPOL_MF_MOVE_ALL bits, code breaks and passing origin pte - 1 to
pte_unmap_unlock seems like not a good idea.
queue_pages_pte_range can run in MPOL_MF_MOVE_ALL mode which doesn't
migrate misplaced pages but returns with EIO when encountering such a
page. Since commit a7f40cfe3b7a ("mm: mempolicy: make mbind() return
-EIO when MPOL_MF_STRICT is specified") and early break on the first pte
in the range results in pte_unmap_unlock on an underflow pte. This can
lead to lockups later on when somebody tries to lock the pte resp.
page_table_lock again..
Fixes: a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified")
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Feilong Lin <linfeilong@huawei.com>
Cc: Shijie Luo <luoshijie1@huawei.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201019074853.50856-1-luoshijie1@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/signal.c')
0 files changed, 0 insertions, 0 deletions