Re: [PATCH v22 12/23] LSM: Specify which LSM to display

On 11/5/2020 1:22 AM, Greg KH wrote: > On Wed, Nov 04, 2020 at 03:41:03PM -0800, Casey Schaufler wrote: >> Create a new entry "display" in the procfs attr directory for >> controlling which LSM security information is displayed for a >> process. A process can only read or write its own display value. >> >> The name of an active LSM that supplies hooks for >> human readable data may be written to "display" to set the >> value. The name of the LSM currently in use can be read from >> "display". At this point there can only be one LSM capable >> of display active. A helper function lsm_task_display() is >> provided to get the display slot for a task_struct. >> >> Setting the "display" requires that all security modules using >> setprocattr hooks allow the action. Each security module is >> responsible for defining its policy. >> >> AppArmor hook provided by John Johansen <john.johansen(a)canonical.com&gt; >> SELinux hook provided by Stephen Smalley <sds(a)tycho.nsa.gov&gt; >> >> Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; >> Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; >> Acked-by: Paul Moore <paul(a)paul-moore.com&gt; >> Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; >> Cc: linux-api(a)vger.kernel.org >> --- >> fs/proc/base.c | 1 + >> include/linux/lsm_hooks.h | 17 +++ >> security/apparmor/include/apparmor.h | 3 +- >> security/apparmor/lsm.c | 32 +++++ >> security/security.c | 169 ++++++++++++++++++++++++--- >> security/selinux/hooks.c | 11 ++ >> security/selinux/include/classmap.h | 2 +- >> security/smack/smack_lsm.c | 7 ++ >> 8 files changed, 223 insertions(+), 19 deletions(-) >> >> diff --git a/fs/proc/base.c b/fs/proc/base.c >> index 0f707003dda5..7432f24f0132 100644 >> --- a/fs/proc/base.c >> +++ b/fs/proc/base.c >> @@ -2806,6 +2806,7 @@ static const struct pid_entry attr_dir_stuff[] = { >> ATTR(NULL, "fscreate", 0666), >> ATTR(NULL, "keycreate", 0666), >> ATTR(NULL, "sockcreate", 0666), >> + ATTR(NULL, "display", 0666), > That's a vague name, any chance it can be more descriptive? Sure. How about lsm_display, or display_lsm? I wouldn't say that any of the files in /proc/*/attr have especially descriptive names, but that's hardly an excuse.