This is a note to let you know that I've just added the patch titled

mm: fail get_vaddr_frames() for filesystem-dax mappings

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: mm-fail-get_vaddr_frames-for-filesystem-dax-mappings.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From b7f0554a56f21fb3e636a627450a9add030889be Mon Sep 17 00:00:00 2001

From: Dan Williams dan.j.williams@intel.com Date: Wed, 29 Nov 2017 16:10:39 -0800 Subject: mm: fail get_vaddr_frames() for filesystem-dax mappings

From: Dan Williams dan.j.williams@intel.com

commit b7f0554a56f21fb3e636a627450a9add030889be upstream.

Until there is a solution to the dma-to-dax vs truncate problem it is not safe to allow V4L2, Exynos, and other frame vector users to create long standing / irrevocable memory registrations against filesytem-dax vmas.

[dan.j.williams@intel.com: add comment for vma_is_fsdax() check in get_vaddr_frames(), per Jan] Link: http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.stgit@dwilli... Link: http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.stgit@dwilli... Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Dan Williams dan.j.williams@intel.com Reviewed-by: Jan Kara jack@suse.cz Cc: Inki Dae inki.dae@samsung.com Cc: Seung-Woo Kim sw0312.kim@samsung.com Cc: Joonyoung Shim jy0922.shim@samsung.com Cc: Kyungmin Park kyungmin.park@samsung.com Cc: Mauro Carvalho Chehab mchehab@kernel.org Cc: Mel Gorman mgorman@suse.de Cc: Vlastimil Babka vbabka@suse.cz Cc: Christoph Hellwig hch@lst.de Cc: Doug Ledford dledford@redhat.com Cc: Hal Rosenstock hal.rosenstock@gmail.com Cc: Jason Gunthorpe jgg@mellanox.com Cc: Jeff Moyer jmoyer@redhat.com Cc: Ross Zwisler ross.zwisler@linux.intel.com Cc: Sean Hefty sean.hefty@intel.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- mm/frame_vector.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)

--- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -53,6 +53,18 @@ int get_vaddr_frames(unsigned long start ret = -EFAULT; goto out; } + + /* + * While get_vaddr_frames() could be used for transient (kernel + * controlled lifetime) pinning of memory pages all current + * users establish long term (userspace controlled lifetime) + * page pinning. Treat get_vaddr_frames() like + * get_user_pages_longterm() and disallow it for filesystem-dax + * mappings. + */ + if (vma_is_fsdax(vma)) + return -EOPNOTSUPP; + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { vec->got_ref = true; vec->is_pfns = false;

Patches currently in stable-queue which might be from dan.j.williams@intel.com are

queue-4.14/mm-hugetlbfs-introduce-split-to-vm_operations_struct.patch queue-4.14/ib-core-disable-memory-registration-of-filesystem-dax-vmas.patch queue-4.14/mm-introduce-get_user_pages_longterm.patch queue-4.14/mm-fail-get_vaddr_frames-for-filesystem-dax-mappings.patch queue-4.14/device-dax-implement-split-to-catch-invalid-munmap-attempts.patch queue-4.14/v4l2-disable-filesystem-dax-mapping-support.patch queue-4.14/mm-fix-device-dax-pud-write-faults-triggered-by-get_user_pages.patch queue-4.14/mm-madvise.c-fix-madvise-infinite-loop-under-special-circumstances.patch