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| author | Peter Xu <peterx@redhat.com> | 2023-11-23 13:02:22 -0500 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-10 16:51:52 -0800 |
| commit | e9119fb65761f124b31743b598ce04b8f15a6fe3 (patch) | |
| tree | 8f9808b829310b9e3c4924fa2a7b13d150c935e5 /mm/oom_kill.c | |
| parent | ac3f3b0a55518056bc80ed32a41931c99e1f7d81 (diff) | |
| download | linux-e9119fb65761f124b31743b598ce04b8f15a6fe3.tar.gz linux-e9119fb65761f124b31743b598ce04b8f15a6fe3.tar.bz2 linux-e9119fb65761f124b31743b598ce04b8f15a6fe3.zip | |
mm/gup: fix follow_devmap_p[mu]d() on page==NULL handling
This is a bug found not by any report but only by code observations.
When GUP sees a devpmd/devpud and if page==NULL is returned, it means a
fault is probably required. Here falling through when page==NULL can
cause unexpected behavior.
Fix both cases by catching the page==NULL cases with no_page_table().
Link: https://lkml.kernel.org/r/20231123180222.1048297-1-peterx@redhat.com
Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Fixes: 080dbb618b4b ("mm/follow_page_mask: split follow_page_mask to smaller functions.")
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/oom_kill.c')
0 files changed, 0 insertions, 0 deletions