On Thu, Sep 27, 2018 at 9:17 PM Casey Schaufler <[email protected]> wrote: > > From: Casey Schaufler <[email protected]> > > The PTRACE_MODE_SCHED check erroniously returns 0 in > all cases. It should be returning -EPERM. This fixes > the logic to correct that error. > > Signed-off-by: Casey Schaufler <[email protected]>
Reviewed-by: Jann Horn <[email protected]> > --- > security/commoncap.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/security/commoncap.c b/security/commoncap.c > index e77457110d05..70a7e3d19c16 100644 > --- a/security/commoncap.c > +++ b/security/commoncap.c > @@ -152,9 +152,8 @@ int cap_ptrace_access_check(struct task_struct *child, > unsigned int mode) > if (cred->user_ns == child_cred->user_ns && > cap_issubset(child_cred->cap_permitted, *caller_caps)) > goto out; > - if (mode & PTRACE_MODE_SCHED) > - goto out; > - if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) > + if (!(mode & PTRACE_MODE_SCHED) && > + ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) > goto out; > ret = -EPERM; > out: > -- > 2.17.1 >
