Messages in this thread | | | Date | Mon, 30 Jul 2012 10:00:00 -0700 | Subject | Re: yama_ptrace_access_check(): possible recursive locking detected | From | Kees Cook <> |
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On Thu, Jul 26, 2012 at 8:41 AM, Oleg Nesterov <oleg@redhat.com> wrote: > On 07/26, Fengguang Wu wrote: >> >> Here is a recursive lock possibility: >> >> ptrace_may_access() >> => task_lock(task); >> yama_ptrace_access_check() >> get_task_comm() >> => task_lock(task); > > I think yama_ptrace_access_check() can simply use ->comm > > Oleg. > > --- x/security/yama/yama_lsm.c > +++ x/security/yama/yama_lsm.c > @@ -279,12 +279,9 @@ static int yama_ptrace_access_check(stru > } > > if (rc) { > - char name[sizeof(current->comm)]; > printk_ratelimited(KERN_NOTICE > "ptrace of pid %d was attempted by: %s (pid %d)\n", > - child->pid, > - get_task_comm(name, current), > - current->pid); > + child->pid, current->comm, current->pid); > } > > return rc; >
Great catch, thanks! I've sent Oleg's suggestion (with an added comment) separately.
-Kees
-- Kees Cook Chrome OS Security
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