The patch titled
Subject: mm/memory.c: prevent mapping typed pages to userspace
has been added to the -mm tree. Its filename is
mm-prevent-mapping-typed-pages-to-userspace.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-prevent-mapping-typed-pages-to-userspace.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-prevent-mapping-typed-pages-to-userspace.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Subject: mm/memory.c: prevent mapping typed pages to userspace
Pages which use page_type must never be mapped to userspace as it would
destroy their page type. Add an explicit check for this instead of
assuming that kernel drivers always get this right.
Link: http://lkml.kernel.org/r/20190129053830.3749-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memory.c~mm-prevent-mapping-typed-pages-to-userspace
+++ a/mm/memory.c
@@ -1452,7 +1452,7 @@ static int insert_page(struct vm_area_st
spinlock_t *ptl;
retval = -EINVAL;
- if (PageAnon(page) || PageSlab(page))
+ if (PageAnon(page) || PageSlab(page) || page_has_type(page))
goto out;
retval = -ENOMEM;
flush_dcache_page(page);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-remove-sysctl_extfrag_handler.patch
mm-remove-redundant-test-from-find_get_pages_contig.patch
mm-prevent-mapping-slab-pages-to-userspace.patch
mm-prevent-mapping-typed-pages-to-userspace.patch
