lkml.org 
[lkml]   [2018]   [Sep]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectSmack: wrong-looking capable() check in smk_ptrace_rule_check()
Hi!

I noticed the following check in smk_ptrace_rule_check():

if (tracer_known->smk_known == tracee_known->smk_known)
rc = 0;
else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
rc = -EACCES;
else if (capable(CAP_SYS_PTRACE))
rc = 0;
else
rc = -EACCES;

Note that smk_ptrace_rule_check() can be called from not just
smack_ptrace_access_check() and smack_ptrace_traceme(), but also
smack_bprm_set_creds(). AFAICS this means that if a task executes with
a smack privilege transition and smack_ptrace_rule is
SMACK_PTRACE_EXACT, whether the execution is permitted depends on
whether _the debugged task_ has CAP_SYS_PTRACE (and not on whether the
debugger has that capability).
This seems like it's probably unintentional?

\
 
 \ /
  Last update: 2018-09-06 20:24    [W:0.040 / U:1.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site