[PATCH 0/2] mm: make copy_to_kernel_nofault() not fault on user addresses

Omar Sandoval <osandov@xxxxxxxxxxx> · Sun, 1 Sep 2024 22:31:27 -0700

From: Omar Sandoval <osandov@xxxxxx>

Hi,

I hit a case where copy_to_kernel_nofault() will fault (lol): if the
destination address is in userspace and x86 Supervisor Mode Access
Prevention is enabled. Patch 2 has the details and the fix. Patch 1
renames a helper function so that its use in patch 2 makes more sense.
If the rename is too intrusive, I can drop it.

Thanks,
Omar

Omar Sandoval (2):
  mm: rename copy_from_kernel_nofault_allowed() to
    copy_kernel_nofault_allowed()
  mm: make copy_to_kernel_nofault() not fault on user addresses

 arch/arm/mm/fault.c         |  2 +-
 arch/loongarch/mm/maccess.c |  2 +-
 arch/mips/mm/maccess.c      |  2 +-
 arch/parisc/lib/memcpy.c    |  2 +-
 arch/powerpc/mm/maccess.c   |  2 +-
 arch/um/kernel/maccess.c    |  2 +-
 arch/x86/mm/maccess.c       |  4 ++--
 include/linux/uaccess.h     |  2 +-
 mm/maccess.c                | 10 ++++++----
 9 files changed, 15 insertions(+), 13 deletions(-)

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2.46.0