linux/security
Paul Moore a7e4676e8e selinux: remove the 'checkreqprot' functionality
We originally promised that the SELinux 'checkreqprot' functionality
would be removed no sooner than June 2021, and now that it is March
2023 it seems like it is a good time to do the final removal.  The
deprecation notice in the kernel provides plenty of detail on why
'checkreqprot' is not desirable, with the key point repeated below:

  This was a compatibility mechanism for legacy userspace and
  for the READ_IMPLIES_EXEC personality flag.  However, if set to
  1, it weakens security by allowing mappings to be made executable
  without authorization by policy.  The default value of checkreqprot
  at boot was changed starting in Linux v4.4 to 0 (i.e. check the
  actual protection), and Android and Linux distributions have been
  explicitly writing a "0" to /sys/fs/selinux/checkreqprot during
  initialization for some time.

Along with the official deprecation notice, we have been discussing
this on-list and directly with several of the larger SELinux-based
distros and everyone is happy to see this feature finally removed.
In an attempt to catch all of the smaller, and DIY, Linux systems
we have been writing a deprecation notice URL into the kernel log,
along with a growing ssleep() penalty, when admins enabled
checkreqprot at runtime or via the kernel command line.  We have
yet to have anyone come to us and raise an objection to the
deprecation or planned removal.

It is worth noting that while this patch removes the checkreqprot
functionality, it leaves the user visible interfaces (kernel command
line and selinuxfs file) intact, just inert.  This should help
prevent breakages with existing userspace tools that correctly, but
unnecessarily, disable checkreqprot at boot or runtime.  Admins
that attempt to enable checkreqprot will be met with a removal
message in the kernel log.

Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-20 12:33:50 -04:00
..
apparmor capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -08:00
bpf
integrity powerpc updates for 6.3 2023-02-25 11:00:06 -08:00
keys This update includes the following changes: 2023-02-21 18:10:50 -08:00
landlock landlock: Support file truncation 2022-10-19 09:01:44 +02:00
loadpin LoadPin: Allow filesystem switch when not enforcing 2023-01-19 15:18:20 -08:00
lockdown lockdown: ratelimit denial messages 2022-09-14 07:37:50 -04:00
safesetid LSM: SafeSetID: Add setgroups() security policy handling 2022-07-15 18:24:42 +00:00
selinux selinux: remove the 'checkreqprot' functionality 2023-03-20 12:33:50 -04:00
smack One fix for resetting CIPSO labeling. 2023-02-22 12:52:59 -08:00
tomoyo tomoyo: Update website link 2023-01-13 23:11:38 +09:00
yama
commoncap.c capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -08:00
device_cgroup.c device_cgroup: Roll back to original exceptions after copy failure 2022-11-16 18:28:55 -05:00
inode.c
Kconfig x86/retbleed: Add fine grained Kconfig knobs 2022-06-29 17:43:41 +02:00
Kconfig.hardening randstruct: disable Clang 15 support 2023-02-08 15:26:58 -08:00
lsm_audit.c audit: Fix some kernel-doc warnings 2022-10-28 06:37:55 -04:00
Makefile
min_addr.c
security.c integrity-v6.3 2023-02-22 12:36:25 -08:00