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

From: jeffxu
Date: Wed Jul 05 2023 - 02:33:29 EST


From: Jeff Xu <jeffxu@xxxxxxxxxx>

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@xxxxxxxxxxxxx> who reported the bug.
see [1] for context.

[1] https://lore.kernel.org/linux-mm/CABi2SkXUX_QqTQ10Yx9bBUGpN1wByOi_=gZU6WEy5a8MaQY3Jw@xxxxxxxxxxxxxx/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@xxxxxxxxxx/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