[PATCH v2 0/2] mm/memfd: fix sysctl MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED

[jeffxu at chromium.org]

From: Jeff Xu <jeffxu at google.com>

When sysctl vm.memfd_noexec is 2 (MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED),
memfd_create(.., MFD_EXEC) should fail.

This complies with how MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED is
defined - "memfd_create() without MFD_NOEXEC_SEAL will be rejected"

Thanks to Dominique Martinet <asmadeus at codewreck.org> who reported the bug.
see [1] for context.

[1] https://lore.kernel.org/linux-mm/CABi2SkXUX_QqTQ10Yx9bBUGpN1wByOi_=gZU6WEy5a8MaQY3Jw@mail.gmail.com/T/

History:
V2: fix build error when CONFIG_SYSCTL is not defined. 

V1: initial version
https://lore.kernel.org/linux-mm/20230630031721.623955-3-jeffxu@google.com/T/

Jeff Xu (2):
  mm/memfd: sysctl: fix MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED
  selftests/memfd: sysctl: fix MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED

 mm/memfd.c                                 | 57 +++++++++++++---------
 tools/testing/selftests/memfd/memfd_test.c |  5 ++
 2 files changed, 38 insertions(+), 24 deletions(-)

-- 
2.41.0.255.g8b1d071c50-goog