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| author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2017-09-18 16:51:51 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-05 09:44:01 +0200 |
| commit | 22338c55658d888326bd1998f8d4328c76809053 (patch) | |
| tree | 6f93e60d9361973dd87165ede3caaaed4593e32c /drivers/base | |
| parent | c76655fb0f448de4cfadc83d3266c05a0a3c5dc0 (diff) | |
s390/mm: fix write access check in gup_huge_pmd()
commit ba385c0594e723d41790ecfb12c610e6f90c7785 upstream.
The check for the _SEGMENT_ENTRY_PROTECT bit in gup_huge_pmd() is the
wrong way around. It must not be set for write==1, and not be checked for
write==0. Fix this similar to how it was fixed for ptes long time ago in
commit 25591b070336 ("[S390] fix get_user_pages_fast").
One impact of this bug would be unnecessarily using the gup slow path for
write==0 on r/w mappings. A potentially more severe impact would be that
gup_huge_pmd() will succeed for write==1 on r/o mappings.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
0 files changed, 0 insertions, 0 deletions