Messages in this thread Patch in this message | | | From | John Stultz <> | Subject | [PATCH 2/2 v4] proc: Add LSM hook checks to /proc/<tid>/timerslack_ns | Date | Thu, 21 Jul 2016 13:24:27 -0700 |
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As requested, this patch checks the existing LSM hooks task_getscheduler/task_setscheduler when reading or modifying the task's timerslack value.
Previous versions added new get/settimerslack LSM hooks, but since they checked the same PROCESS__SET/GETSCHED values as existing hooks, it was suggested we just use the existing ones.
Cc: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> CC: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: James Morris <jmorris@namei.org> Cc: Android Kernel Team <kernel-team@android.com> Cc: linux-security-module@vger.kernel.org Cc: selinux@tycho.nsa.gov Signed-off-by: John Stultz <john.stultz@linaro.org> --- v2: * Initial swing at adding settimerslack LSM hook v3: * Fix current/p switchup bug noted by NickK * Add gettimerslack hook suggested by NickK v4: * Dropped adding get/settimerslack LSM hooks, and just reuse the get/setscheduler ones.
fs/proc/base.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/fs/proc/base.c b/fs/proc/base.c index c94abae..02f8389 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2286,6 +2286,12 @@ static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, goto out; } + err = security_task_setscheduler(p); + if (err) { + count = err; + goto out; + } + task_lock(p); if (slack_ns == 0) p->timer_slack_ns = p->default_timer_slack_ns; @@ -2314,6 +2320,10 @@ static int timerslack_ns_show(struct seq_file *m, void *v) goto out; } + err = security_task_getscheduler(p); + if (err) + goto out; + task_lock(p); seq_printf(m, "%llu\n", p->timer_slack_ns); task_unlock(p); -- 1.9.1
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